You are viewing the version of this documentation from Perl blead. This is the main development branch of Perl. (git commit 63b30a217f0590c255f9ccdb893dc2fa51bc68b0)
elseif

The "else if" keyword is spelled elsif in Perl. There's no elif or else if either. It does parse elseif, but only to warn you about not using it.

See the documentation for flow-control keywords in "Compound Statements" in perlsyn.