In order to record all the known collisions—that is, cases where two or more names encode to the same six-letter abbreviation according to the rules for abbreviation formation—you must add to the alternate forms file one line for each collision. Each such line enumerates all the disambiguations, that is, the substitute form codes that are preferred:
Enter the collision code in the first six columns.
Enter a question mark (
in the seventh column.
Type all the disambiguations separated by colon
Examples of collision records:
barowl?brdowl:brnowl belspa?bldspa:bllspa columb?colba :colbid:colbin
The first example shows that two names collide for the
barowl. The forms are
Barred Owl (which is given the substitute code
brdowl in the standard forms
file) and Barn Owl, with substitute code
The last example shows a three-way collision for code
columb between the codes for
genus Columba, family Columbidae,
and subfamily Columbinae. Note that a collision record
may refer to forms other than standard taxa.