4.10. [if-field] etc.
The least-compatible things in the tag area are [if-field] (needs to be [if-PREFIX-field], where prefix might be item|loop by default depending on the tag. Likewise:
[if-data table col] --> [if-PREFIX-data table col] [on-change mark] --> [PREFIX-change mark] [if-param param] --> [if-PREFIX-param param] [PREFIX-param N] --> [PREFIX-pos N] (where N is a digit)