# System Parameters

'OM' | Old Style Mask

## Description

Defines the behavior of the MSK( ) function.

0 | MSK( ) supports industry standard Perl compatible RegEx.
1 | MSK( ) supports POSIX compatible RegEx, the same as Unix Grep.
2 | MSK( ) supports a sub-set of POSIX compatible RegEx. Where: The | operator works on the character that precedes it and comes after it unless parentheses are used. Example: "cat|dog|pig" does not match "I want a cat". To match, you need to use the pattern "(cat)|(dog)|(pig)". #### Note: This is a legacy mode retained for compatibility.

## Default

'OM'=0

## See Also

MSK( ) Scan String for Mask