in reply to Unable to pass 0 number through form with CGI DBI backend

As marto pointed out, the character class of your data laundering substitution is not what you think it to be. 

perl -le 'print $%'
0

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See perlvar. Escape the $ in your character class with a backslash.

perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'

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