Copy TLEN to Length

[ohrenkino]

The tag panel does not show any properties with a name starting with an underscore (at the moment).

@Beat

Do I need to use Actions (Alt-6) or Scripting ?

oops, I never pasted the FAQ thread.
Here it is:

Actions and batch-operations

How to copy one field value to another field? Example how to copy the content of the ARTIST field to the ALBUMARTIST field: Create a new action in an existing action group or make a new action group. Action type: Format value Field: ALBUMARTIST Format string: %artist% Note: If you want to copy all possible values of a field (in case you have multiple artist fields), the internal scripting function $meta_sep can be used in the format string, e.g., $meta_sep(artist,\\\\)