Macro Language Reference > Macros > Document Preferences > perl_mode
  
perl_mode
Description
A control keyword used with fdpref: specifies optional Perl optimizations.
Syntax
perl_mode options:n
options
Numbers are cumulative, i.e. a value of 3 is options 1 and 2 on.
0
All options off, ie. no optimisation.
1
Syntax error checking disabled
2
Compile Perl snippets