You are viewing the version of this documentation from Perl blead. This is the main development branch of Perl. (git commit 94b79ff119f82f12ab36be7c30e77d9e5f51c0bd)
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.