ID3V2.3 tags?

As title says, I notice that whenever you edit an mp3 with ID3V2.4 tags in mp3tag it changes the tag to ID3V2.3.

Is there anything I can do to keep them at ID3V2.4? Why is it changing them to an older version?

Cheers

RTFM. And set Tools/Options/Tags/MPEG/Write/ID3v2.4.

May I ask why it doesn't do that by default?

ID3V2.3. is the most widely used version of ID3v2 tags. Lots of hardware (for example my MP3 players, discman, car stereo) doesn't support v2.4.