http://www.perlmonks.org?node_id=1026536


in reply to Re^4: Wrong idioms
in thread Wrong idioms

All advice you ever hear about changes to these variables says "change them only in the smallest possible scope and do not call anything that might expect them to be set to the normal values".

And yet, the authorotative source on all special variables contains no such warning. At least I couldn't find one by skimming over the interesting parts.