Substitute placeholder documentation

The p placeholder now supports args to use any preg_replace pattern: p[pattern,replace]

Example: @%p[/\s/,-]|sn%@

Default values are /\s/ and empty string, to remove all spaces as previous behavior.

(from redmine: issue id 5432, created on 2017-03-15, closed on 2017-04-12)

• Relations:
  • copied_to #5428 (closed)
• Custom Fields:
  • Support contract: None