Use Preferences > General Preferences > Tags to configure tags as full-sized or shortened.
To clear all tags:
Segment or Ctrl-Shift+V
Select to clear only the tags from the selected segment.
Document
Select to clear all segment tags for all target segments in the file.
A warning message asks you to agree to clear all tags from the open file.
All tags are cleared for the target segment or for all target segments in the document.