COR003 implicit-external-procedures

warning opt-in

implicit none does not forbid implicit external procedures (implicit none (type, external)).

Why

Plain implicit none still lets a call to an unknown name compile as a reference to an external procedure with an implicit interface: a misspelled procedure name surfaces only at link time, and argument mismatches never. Fortran 2018 implicit none (type, external) turns both into compile errors.

Reported

implicit none

Preferred

implicit none (type, external)

Suppressing

For one occurrence, with the reason on the same line (or alone on the line before the statement):

! fobis: ignore[COR003] <why this occurrence is fine>

For the whole project, ignore = COR003 in the fobos [lint] section.

Equivalent

Fortitude rule C003 (see Lint Rules).