(version 3:10: 29 September 2007).

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Primebase (PBASE) is an attempt by the author to create a digital catalogue all known "True UFO" reports originating from the British Isles and the UK's immediate offshore islands. This project was instigated in mid-1998 and has now reached a stage in 2007 where this on-going project can be shared with other members of the British UFO community. With greater public airing of this data it is hoped that further British “True UFO” reports can be located, while seemingly unknown (but actually spurious events) already contained within it are identified as such. It is further hoped that some of the more sketchy report-summaries can be improved as supplementary information is located.

Primebase’s constituent data comes from a variety of sources; including published accounts, report listings, group journals, magazines and books. The emphasis in this database is on reports that appear seemingly inexplicable. Ideally, one would hope for realms of well-investigated and detailed case reports. However, this is sadly not the case in many instances.  Because of this, Primebase shows the quality of the "UFO" report in question, from probably explicable to possibly "exotic". This allows such marginal cases to be included (to give the broadest picture possible, and to err a little on the side of caution) without any loss of objectivity.

Primebase is different from most sighting catalogues in that it is open about the shortcomings of it's data-sample. It is also unique in that it tries to present a filtered sample of UK sighting reports, focusing on events which appear to be "True UFOs" based on their description (and ideally have undergone some form of evaluation/investigation process).

It should be noted that PRIMEBASE is based on classification systems previously developed by Jenny Randles (Randles 1983 (1) ), Mike Wootten, Paul Fuller and Mike Lewis during the 1980's but subsequently expanded and amended (often drastically) by the author for PBASE. Anyone with knowledge of these systems should be able to understand PBASE case-descriptions with little difficulty. Many of the innovations used in PBASE (i.e. using a date-format field for sorting cases into basic chronological order, and a text-based field for showing the actual case's date, which can often be quite "fuzzy") are attempts to resolve the problems encountered by earlier UFO database classification systems. The original systems (and my amendments) have all been used in bulk-data research projects and are hence capable of representing large number of reports of all conceivable types.



1: PBASE REFERENCE:  The unique PBASE reference for the case in question, shown in the following format; 19770010  (i.e. the year, followed by the PBASE number of the event). In some instances the letter "X" is used to “flag” a probably explicable case; i.e. 19770011X

2: Level:  Investigation level of case (see below).

3: TYPE: This shows the basic attributes of the UFO reported. It is based on the system presented in Jenny Randles book "UFO Reality" (Robert Hale 1983), with some amendments.

4: Def:  Hynek Classification of sighting; see below for specific format (see below).

5: WIT:  (Very) basic description of witness details (see below)..

6: TEXTDATE:  The date (as written in text format) for the sighting concerned generally following this format; 21 Jun 1998. Also uses some abbreviations (explained in greater detail below).

7: TEXTTIME: The time of sighting, using 24-hour clock, written in text format, some abbreviations also used (see below).

8: TIMETYPE:  Shows whether stated time is either GMT or BST (if blank, GMT/BST status of stated time is uncertain).

9: LOCATION: General textual description of sighting locus.

10: MAAN: Motion and Appearance Anomalies Codified selected aspects of UFO's motion and appearance (explained in greater detail below):

11: Shape:  Basic written description of UFO’s form.

12: Colour:  Basic written description of UFO’s Colour.

Within fields "10" & "11", a  "/" symbol is used to show the hues of different section (s) of a UFO; i.e. a silvery disc-shaped UFO with white lights could be depicted as “[Shape]: Disc/Lights. [Colour] Silver/White”. A "+" symbol shows claimed features of interest associated with a UFO. For example a disc-shaped UFO with a dome and an "aerial" is shown as  “[Shape]: Disc+dome+"aerials".” Lastly, an asterisk symbol ("*") shows changes in a UFO’s colour/shape.  Hence, a UFO which changed colour from White to Yellow would be shown as “[Colour]: White*Yellow”.

13: Duration:  Basic duration of sighting, shown as a 1-figure attribute (see below).

14: Size: Size of UFO, shown as a 1-figure attribute. It has three ways to show size; angular/object sizes, actual/estimated and angular/moon-disc (see below).

15: Details:  Basic description of report. This is presently only 70 characters in length.

16: ARLOC (ARea LOcation Classification): Shows the basic geographical part of the UK from which the report originated from. For example the ARLOC rating for a report from the West Country is EY (se below).

17: S/P: This represents the report’s Strangeness/Probability rating, as described in APPENDIX 1, below. As of 2007 this rating is being incorporated into the existing dataset.

18: SIGHTING EVALUATION: In this system shows the grade of UFO concerned (as explained below).

19: INVESTIGATOR:  Shows the person(s)/Group who investigated this report.

20: SOURCE: The UFO group reference of the sighting concerned; either an actual group reference or the magazine in which the report was taken from.

21: CHRN:  Chronological date-format field. Mostly a "back office" function used to sort reports into specific date order. In UK full-year format 12/12/1988.




Investigation level:

LEVEL A: Full On site inquiry by experienced investigators.

LEVEL B: Follow-up interview only, or full investigation but by probationary investigators.

LEVEL C: Witness completes report forms but no follow-up.

LEVEL D: Written account by witness only, no investigator involvement.

LEVEL E: Entirely third hand data e.g., press cuttings  (can also be shown as "L" for letter or  "N" for newsclipping, "U"  for basic, sketchy report   noted by a Ufologist).

LEVEL X: Official Investigation (equivalent to Level "A").

LEVEL Y: Official Investigation (equivalent to Level "B").

LEVEL Z: Official Investigation (equivalent to Level "C").



AL       =            "Nocturnal Lights."

BD      =            "Daylight Disc".

Suffix:           +  V                 =          Radar Visual.

                     +  X                 =          Radar Contact only.

C1       =            CE I

C2       =            CE II

C3       =            CE III

C4       =            CE IV

The non-standard notation ("AL" and "BD" instead of "NL" and "DD" ) is employed within PRIMEBASE  to enable records to be sorted in correct Hynek classification sequence.



England                      =            E            North              =            O

Ireland                        =            I              Midlands        =            M

Northern Ireland         =            B            West               =            Y

Scotland                     =            H            South             =            S

Wales                         =            W            Coastal         =            T


Date Abbreviations:     

Date:                                                  Time

Aut:     =            Autumn                      Eve               =       Evening.

Sum:   =            Summer                     Night            =       Night.

Win:    =            Winter                        Day              =       Day.

Spr:     =            Spring                        Morn            =       Morning.

Lat:      =            Late                           Aft                =       Afternoon.

Mid:     =            Middle                        Dusk            =      Dusk.

Ear:     =            Early                          Dawn            =      Dawn.


Month Abbreviations:

Jan      =           January.                   Jul             =            July.

Feb     =            February.                  Aug           =            August.

Mar     =            March.                      Sep           =            September.

Apr      =            April.                         Oct            =            October.

May     =            May.                         Nov           =            November.

Jun       =           June.                       Dec           =             December.

Default dates used in "Chron" field when exact date of sighting unknown;



 VISUAL: General visual aspect of UFO:

 "Distants" (i.e. LITS, NLs, LDs, DDs & MDs) are shown by using a low-case letter on "Visual" Matrix.  (.i.e. v/a/w + visual aspect). CEs 1-4 are shown via using a high-case letter on "Visual" Matrix. (ie V/A/W + visual aspect).


v/VX:   No visual sighting of  a UFO.                                                     

v/V0:   Poorly-defined/hazy/cloudy form                                               

v/V1:   Form Resembled a light, or a cluster of Lights                         

v/V2:   UFO possessed a (basic) defined shape (default).                                               

v/V3:   Form with a clearly defined shape with additional

           surface features (i.e. "panels", "domes", etc).                            

v/V4:   Anomalous Form; extreme and diverse changes

           of shape, etc                                                                              

v/V5:  Special; mixed shape-types of UFOs seen.  

n/a.   Contradictory shape descriptions. etc.



Although PRIMEBASE includes a “Shape” description parameter, the wide variety of terms used by witnesses often render searches for specific shape-types difficult. Hence, PRIMEBASE includes a shape-code definition within the "Type" field. This system grades UFO shapes into 2 main classes, which are themselves divided into 3 main-subtypes. The categories record general shape-type only; slight differences in stated configuration are disregarded.


"Classical" Uforms:

These include the most common "classical" UFO shape-types:

(1) Lights, balls & spheres                    ("B"),

(2) Discs                                                ("D"),

(3) Cigars or tubes                                 ("T")

Non-classical Uforms:


All forms other than above. These include;

(1) Non-classical forms                           ("N")

(2) Unusual forms                                   ("U")


(3) Further forms                                     ("F")  

  (currently a "reserved" category)

Lower-case usage = "doubled" form; i.e such as a "dumbbell” shaped UFO ("b3").



B:            Spherical

1:         Star-like.

2:            Cluster of lights.

3:            Sphere.

4:            Sphere/Oval bisected by rim ("Saturn" shaped).

5:            Teardrop.

6:            Round.

7:            Torus/ring/Wheel.

8:            (reserved).

9:            (reserved).

0:            Unclear; but generally a shape-type included on this table.


D:        Disclike:

1            Saucer.

2            Lens.

3:            Ovoid/Elliptical ("Egg-shaped").

4:            Dome/Saucer, bisected by rim.

5:           Coin-like.

6:            Hat/Bell shaped ("Domed-Disc").

7:            Inverted-Pan (i.e. Oblong with sloped sides; like the "McMinville UFO").

8:            Dome/Basin-like/mushroom-shaped.

9:            (reserved).

0:            Unclear; but generally a shape-type included on this table.


T:          Tubular.

1:          Contrail-like.

2:          Tubular/cylindrical/Oblong/Spindle.

3:          Cigar (tube,curved sides).

4:          Bullet-Shell shaped.

5:          Cross/Aircraft shaped.

6:          Dart/Rocket-like.

7:          Vee/Boomerang/Crescent.

8:          Frame/Spring-like.

9:          "Bent-Tube"/Letter/Number shaped.

0:           Unclear; but generally a shape-type included on this table.

            Lower-case usage = "doubled" form; i.e a "dumbbell" shaped UFO is a b3.



N:        Nonclassical (general):

1:         Triangular-shaped.

2:         Cone-shaped.

3:         Hexagonal.

4:         Lozenge/Diamond shape(round or curved edges).

5:         Tub/Barrel-shaped.

6:         Cube.

7:         Square/Flat oblong.

8:         Lifting Body/Heel shape.

9:         (reserved)

0:         Unclear


U:           UNUSUAL FORMS:

1            Nebulous/Hazy/Glow-like

             (no actual specific form)

2            Constantly shape-shifting form.

3            (reserved).

4            (reserved).

5            (reserved).

6            (reserved).

7:       7:           Mixture of shapes observed. (NB does *not* apply to UFOs ejecting/absorbing other forms; notes shape of main form only).

8:           Contradictory shape description.

9:           Unclear, but form unlike those covered

              by tables "B","D","T" or "N".

0:          No actual shape given in case description!


F:            FURTHER FORMS:

1:            (Reserved).

2:            (Reserved).

3:            (Reserved).

4:            (Reserved).

5:            (Reserved).

6:            (Reserved).

7:            (Reserved).

8:            (Reserved).

9:            (Reserved).

0:            (Reserved).


RESPONSIVES: A phenomenon which seems to respond to the witness

                                                                                                                        (Hynek Class):

R1: Where the response is IMPLIED i.e. UFO reacts to witness action.

R2:  Where the phenomenon pursues the witness.

R3:  Where the phenomenon causes immobilisation.                                  (CEII)

R4:  Where the phenomenon responds to animals.

R5:  Where the phenomenon responds to other objects i.e., aircraft etc.


LANDINGS: Where the phenomenon is perceived to land.


L1: Where the landing has no apparent effect,                                               (CEI)

L2: Where the landing involves physiological effects.                                    (CEII)

L3: Where the landing affects nearby animals.                                              (CEII)

L4: Where the landing leaves residual traces.                                               (CEII)

L5: Where the phenomenon is seen underwater.



EFFECTIVES: Where the phenomenon has an interactive effect with:

E1: The witness.                                                                                            (CEII)

E2: The environment.                                                                                       (CEII)

E3: Mechanical equipment.                                                                              (CEII)

E4: Animals.                                                                                                      (CEII)

E5: Oz Factor/Missing time noted in sighting account.

E6: Psychical aspects to case (listed under "E5" when associated with "Oz factor/Missing time" events).


Instrumentally-Detected Events:


IX:  Abortive attempt to film/photograph UFO.

I0:  Optical device used predominantly to view UFO.

I1:  Still photographs taken.

I2:  Movie-quality film taken.

I3:  RADAR (or similar) device detected presence of UFO.                                (RV/R)

I4:  Other detector/Sensor type registered presence of UFO.

I5:  Camcorder(or camcorder quality) footage taken.

I6   Tape recorder used to record ongoing facet of sighting.

I7:  Several audio/optical devices used to record presence of UFO.

I8:  Several audio/optical devices used to record presence of UFO,

      RADAR/ other sensor registered it's presence.

I7:  Several of these devices used during sighting.


OCCUPIEDS: Where occupants are perceived in the presence of a UFO;

O1: Those who simply fly by or are observers.                                             (CEIII)

O2: Those who take material samples.                                                         (CEIII)

O3: Those who repair or are technicians,                                                     (CEIII)

O4: Those who examine or question.                                                            (CEIII)


 CONTACTS: Where contact occurs between phenomenon and witness.

NB: "H" is used in place of "C" for "Contact" cases where details of contact have been acquired via hypnosis.

C1:     By means of simple meeting.                                                                (CEIII)

C2:     With some kind of assault or force.                                                       (CEIII)

C3:     Abduction into UFO.                                                                              (CEIV)

C4:     Abduction with apparent residual memory loss.                                    (CEIV)

C5:     Contact by non-verbal means.                                                              (CEIV)

C6:     Contact by way of vision or dream.                                                       (CEIV)

H/C7:   Witness entered UFO by request or curiosity.                                     (CEIV)

H/C8:  "MIB" type activity associated with case.


Entity Types:

Entity Size:

G:       Giant; size greater than six foot.

M:        Medium; size 6ft to 5ft 1 inch.

S:        Small; less than 5ft, 1 inch.

J:         Various sizes/Mixed

Q:        Not known.


Entity Type:

1          "Human"; totally human in form.

2          "Coversuited Human(iod)"; Human-like figure enveloped in all-over "outfit"

3          "Humanlike"; Human, but with several differing features.

4          "Humanoid"; Human in basic form, but notably non-human.

5          "Humanoid/machine-like"; Human in shape, but stated to a "robot".

6          "Non-Humanoid/"Machine-like"; entity with non-human shape is stated to resemble a "machine".

7          "Non-Humanoid/Morphic"; Non human in shape but possessing an solid organic shape

8          "Non-Humanoid/Non morphic; Non-human in shape, resembling a "blob" or other exotic, non-human shape.

9          Mixed types of entities reported/alleged.


Witness Code Parameters:

 CATEGORY: Observational qualify of witness(es)

A: One or more professional observers i.e., pilot, astronomer etc.

B: 1+ experienced observers, not necessarily professional; but of good standing, i.e. police etc.

C: No experienced observers.


GROUP: Number of witnesses.

1:Two or more independent witnesses at different locations.

2: Two or more witnesses at one location.

3: One witness only.


 General shorthand notation (used in “Colour”, “Shape” and “Description” fields):    

& = and              * = Changed to             / = Specific part of UFO  @ = Also                + = With               

Multi = Multiple.


Duration Parameter:

0          0-9 seconds.

1          10-29 seconds.

2          30-59 seconds.

3          1-2 minutes.

4          3-4 minutes.

5          5-9 minutes.

6          10-29 minutes.

7          30-59 minutes.

8          1 hour.

9          2 hours or more


Size Parameter:

1          Pinhead.

2          Pea

3          [Halfpenny] Larger than a Pea but smaller than a Penny

4          Penny

5          Two pence

6          Golfball

7          Tennis Ball

8          Large (151+ ft).

9          Aircraft sized (16-150 ft)

0          Small (15 ft or less).

A         Less than angular size of a Full Moon

b          (Three-Fourths to a Half).

c          (less than half).                                           

d          (Star).                                                            

M         Equal to angular size of a Full Moon 

y          (No more than 2 Moon-Diameters).             .

w         (3-4 Moon-diameters).

v          (5-6 Moon-diameters).

u          (Greater than 6 moon-diameters).

Z          Larger than angular size of Full Moon


MAAN (Motion & Appearance ANomalies):

This section covers notable motion and shape aspects of a reported UFO, using a single (mnemonic) letter to denote a specific UFO shape/motion factor, as follows:


A:        Alterations; from shape shifting to any notable alteration of UFO's initial form.

B:        Beams; Beams and rays of light emitted by a UFO (includes "solid" light).

C:        Colour changes exhibited by UFO.

D:        "Dome" or similar feature on UFO.

E:         Ejection's; i.e. trails, sparks, etc.   

F:         Features; i.e. "panels", "portholes", "openings", "rivets", etc

G:        Glows: Glows, halos & "mists" seen around a UFO.

H:        Halting: Instantaneous stop(s) while moving at high speed.

I:          Sighting occurred out at sea.

J:         (reserved)

K:         (reserved)

L:         Lights; Lights reportedly located on UFO's body.

M         Motion; Anomalous Motion/trajectory.

N:        Noise; Sound emitted.

O:        Odour; Smell emitted.

P:         Projections; "aerials", "pylons", "fins", "wings",  "rocket pods", "landing gear".

Q:         Quicks: anomalous fast motion(s).

R:         Rotations; Rotation exhibited by UFO.

S:         Starts: instantaneous rapid acceleration while static/at rest.

T:         Turns: anomalous 90* High-Speed turns exhibited.

U:         Other forms ejected/absorbed by UFO.

V:          Vanishings; anomalous (sudden) disappearance.

W:         Wobbling: wobbling, tumbling, flipping actions, etc.

X:          No Special features noted.

Y:          Air-to-Air Encounter.

Z:          More than 1 UFO reported


UFO Classifications Used in PBASE:

UFO/----!         Case widely/officially deemed to be an unknown but probably explicable.

UFO/Open      Case a possible unknown; still under investigation.

UFO/IN            Case may be an unknown, but necessary details currently unclear/absent.

UFO/----?         A rational explanation is possible, but it's validity is open to notable doubt.

UFO/Pmat       Case may be an unknown, but questionable aspects to case.

UFO                Case seems to be an unknown; notably anomalous.

UFO/Good      Case seems to be an unknown; notably anomalous and also passed various evaluation checks.

-----                 Cited cause (balloon, aircraft, meteor, etc.)UFO Subtypes:

EXT:               Exotic; UFO seems to have been a constructed device of contemporary/non human origin.

MMD:              Man-made Device; UFO was quite possibly an unusual experimental unconventional man-made aircraft, RPV etc.

UAP:               UFO was likely to have been a natural, but exotic atmospheric phenomenon.

These are used in the following manner; i.e.  "UFO/Good/UAP, etc.


System abbreviations:

PW     Witness reported a notable number of paranormal experiences.

RW     Witness claimed prior UFO experiences.

RS      Retrospective account; report made more than 4 years after observation reportedly occurred.

YW     Majority of witnesses were aged 16 or less.

m        Magazine

b         Book

k         Booklet/Pamphlet.

r          Report

The last four are used in "Source" field.

 Common magazine abbreviations (also used in "source" field):

 AWR  = Awareness (Contact/UK's magazine). BB = BUFORA BULLETIN; BB(s1); Issues printed between 1982 & 1988. (s2); Issues printed between 1998 to 2005.   BJ= BUFORA Journal  (printed from approx. 1967 to 1981). FSR= Flying Saucer Review.  IC = INCAT (Peter Rogerson's catalogue). MagoniaC = Vallee Magonia catalogue. MJOURN  =  MUFON Journal . NUN = Northern UFO News.   UKUFO = "UFO" Magazine (United Kingdom).  UFODATA = UFOdata magazine. UFOM =  UFO Monthly magazine.    UFOT   =  UFO TIMES (BUFORA).



Strangeness and Probability ratings in PRIMEBASE.


The following table provides a means by which the Strangeness and Probability (S/P) rating of a UFO report (Hynek, 1974 (2) ) can be determined in regard to PRIMEBASE. This is based mostly on a report’s PRIMEBASE parameters, but (ideally) also incorporates data directly taken from the investigation and commentaries concerned with that particular event. Under this system, all sightings are deemed to have a base Strangeness of 0 and a base Probability of 5. This is adjusted by examining the cases’ various PRIMEBASE attributes in the sequence given below, which usually results in an net increase or decrease in the entries’ base S/P rating. Please note all adjustments cited below are cumulative.  At the end of this process, if a case is found to have an apparent Strangeness or Probability value lower than 1, this value is increased to 1.  Likewise, if the final Strangeness or Probability rating is higher than 9, that particular rating is decreased to 9. Within the dataset, the case’s S/P rating is presented as follows: 25, the first figure (i.e. 2) representing a case’s Strangeness rating, the second (i.e. 5) equates to its probability rating.


                                                STRANGENESS                PROBABILITY

Investigation Level:

Level  A                          X                                              +1       

Level  B                          X                                               0

Level  C                          X                                             - 1

Level  D                          X                                             - 2       

Level  X                          X                                              +1

Hynek Class:

                        NL                               0                                              0

                        DD                              0                                              0

                        CE1                            +1                                            0

                        CE2                            see “E”  below                       +1  if evidence tested & validated. 

                                                          -4   if invalidated.

    CE3                             +2                                            0

                        CE4                            +3                                            0


Responsives (R):

                        R1                               +1                                           0

                        R2                               +1                                           0

                        R3                               +1                                           0

                        R4                               +1                                           0


Landings (L):

                        L1                                0                                             0

                        L2                                0                                             0

                        L3                                +1                                           0

                        L4                                +1                                           0

                        L5                                0                                             0         


Effectives (E):

             E1                                0                                              0

                        E2                               0                                              0

                        E3                               0                                              0

                        E4                               0                                              0

                        E5                               +1                                            0

                        E6                               +1                                            0           


Witness Class:

                        A                                 0                                             +2

                        B                                 0                                             +1

                        C                                 0                                               0


Number of Witnesses:

                        1                                  +1                                           +2

                        2                                  0                                             +1

                        3                                  0                                              -2


n.b: If corroborative reports are

made after main sighting have

been publicized:                                  0                                             -1


Witnesses related through

kin or interest/beliefs                           0                                             -1


Serious contradictions

noted in account                                 0                                              -2


Investigation casts some doubt on

witness objectivity                               0                                              -2


Investigation casts serious doubt

on witness objectivity                          0                                              -5


Poorly detailed data-source                0                                              -2

Low credibility data-source                 0                                              -5



I2 – I9: Two or more noted                0                                              +1



Class “H” event                                 -1                                              -2



Two noted                                          +1                                             0

Four+ noted                                       +2                                             0

Grade “X”                                           -1                                              0 



(1)   Randles, J. C. (1983). UFO Reality; A critical look at the physical evidence.  London, U.K; Robert Hale.

(2) Hynek, J. A, (1974).   The UFO Experience, A scientific Inquiry.  London, U.K; Corgi Books.




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