For each non-standard code that is the exact equivalent of a standard code, create a record in the alternate forms file with this format:
Enter the non-standard code, left-justified in the first six columns.
Enter an equal sign (=) in
the seventh column. This is the record type code
for an exact equivalent.
Enter the standard six-letter code for the new name, left-justified in the next six columns.
Enter one space, followed by the English name on which the code is based. Use the inverted order for multi-word names, e.g., “Grebe, light-phase Western”.
Examples of direct-equivalent records:
amboys=blkoys Oystercatcher, American Black amewid=amewig Widgeon, American watpip=amepip Pipit, Water
The form after the equal sign must be defined elsewhere in the standard or alternate forms file. A direct-equivalent record may refer to a code in another direct-equivalent record, but ultimately the chain of references must lead to an actual taxon.
The program will detect cases where there is a cycle
in the chain of references. For example, if BRNOWL refers to COBOWL, but
COBOWL refers to BRNOWL, that is an error.