Sync languages - HTML

Which technique should be used to help syncronized multilingual parallel 
texts marked in HTML.

Some of the principles:
 1.1) If possible, avoid new tag/attribute.

 1.2) The mark must be clearly identify as a sync.

 1.3) It must safely ignored by unconcerned programs.


Some suggestions:
 2.1) NAME (in A)

 2.2) ID

 2.3) A new attribute in SPAN


Tomas