Thread:User talk:CodeCat/PIE entry descendants lists/reply

There is no policy for that in particular, but it is general practice to avoid displaying the same information in several places. This often leads to the two places drifting apart and needing constant synchronisation. If all information is kept in one place, it is easy to keep it organised. We do this with etymologies too; when a word is formed from a compound of two other words, we don't repeat the etymologies of each part of the compounds.