Highlighting uses Colour Coding as described earlier to make fields standout, there are currently two types of highlighter
If there is any whitespace at the start or the end of the value it will be coloured the Whitespace Colour (default pink). This is very useful for identifying white space at the end of a field,if you have ever wondered why two field that appear to have the same value are not listed together in an Audio Player it is probably because one contains white space or undisplayable characters.
You can temporarily highlight fields that match a particular rule, the matching fields are coloured the Highlight Colour (orange). Currently there are two highlight rules available
When enabled all MusicBrainz Recording Ids fields that are the same as in at least one other song are highlighted.