in reply to [SOLVED] Subtle Q: what does 'Apache2::RequestRec' return for missing "param()"?

Excellent!   Thank you!

(Assuming "||" for your "//".)   perldoc perlop

Needs Perl 5.10 though.

After initial effusion, I wound up keeping after because it can be applied to a qw() list of attributes which leverages just one bit of code for all of them.