BUG: My Tag not properly handled in Search (applies to 7.13 B1 and 7.12 stable)

BUG: the My Tag search field does not show in the list of available search fields when searching Your Documents, even though documents such as Clippings have been tagged. 

Expected behavior: proper: as long as any (My) Tag exists in any document or PB, the search field is shown - or pragmatic: the search field is always shown as an available option when searching Your Documents

Beta only or stable: "out in the wild": The bug has been identified in this thread in the L6 forum, since former L6 functionality was lost to current version L7 users. The bug seemingly was introduced sometimes during the L7 release cycle and went unnoticed, it is out in the stable version 7.12 - see Dave's bug notice thread in the L7 forum (currently unanswered).

Workarounds:

• The search field mytag: may be used in the search if explicitly used in the search phrase and will work properly (see the thread where this bug was detected), i.e. tags applied to documents will be found   
  
  
• Since My Tags generated through explicit tagging in Personal Books are not affected by the bug, building a PB that contains at least one tag will reintroduce the functionality to the Search UI. 8255.Test mytag.docx

Repeatability: Consistent. Assuming there exists at least one Clipping from a bible (this will add the bible reference automatically as a My Tag) or any other tagged document, the search field should show up in a Basic Search over Your Documents, but doesn't. 

Using the workaround and building the PB above will add the search field to the list.

Using another source file without the tag for that same PB (like 1460.unTest mytag.docx  )  - seemed to me the easiest way to remove the workaround PB - will remove the My Tag search field from the list.