here - The European Union for Bird Ringing

Circumstances
integer, two digits
The code for circumstances of the encounter has two digits: the first is traditionally referred to as the
primary division. The list of primary divisions is given here. The full list of 2-digit codes can be
downloaded or accessed interactively at:
www.euring.org/data_and_codes/euring_code_list/index.htm
0 Unknown circumstances or unknown whether through man's agency or naturally
(includes attracted to domestic animals).
1 Intentionally by man - shot.
2 Intentionally by man - other means (includes trapped, poisoned, ring number read in
field etc.). All captures (=ringing data) and recaptures (caught and released).
3 Accidentally by man - pollution.
4 Accidentally through human agency (not pollution): includes traffic accidents, collision
with wires etc., entering man-made artefacts, accidents with machinery, drowned at
artificial water. N.b. attracted to domestic animals is 0. Note that 40-42 represent traffic
accidents and 43-45 collisions with static objects.
5 Natural causes - diseases and other natural ailments.
6 Predation by any animal other than man (except hunted by falconer's bird - which
would be covered by 2 above).
7 Other natural causes. Drowned (natural water bodies), trapped, tangled and collided
with natural objects and also weather and starvation or thirst.
8 Bird identified from something else than the metal ring.
99 Totally unknown circumstance: not even stated to be 'found'.
Note that coding of this field is sometimes inter-related with some other fields including Manipulated,
Circumstances Presumed, Moved, Condition.
In all parts of this field where a bird has been reported as dead, the fact of killing is given in the code
entered for the field Condition.
In practice 8|61 (condition=8, circumstances=61) could be used for an apparently healthy bird taken
by a ringer from a cat and released.
Circumstances Presumed
integer, one digit
0 No doubt about the circumstances.
1 Circumstances presumed.
Circumstances Presumed can be used in combination with the entries in the field Circumstances to
modify the circumstances, e.g. Circumstances presumed, code 1, changes 43 'Killed against wires' to
'Found under wires' etc.
EURING exchange-code 2000 Enhanced 24 - 42