Within the musicbrainz.link_type table, the values for link_phrase are inconsistant in that some of them feature trailing spaces, and some don't.

In light of raising this on IRC, with concerns of possible ramifications in displaying these on the site, it was brought to my attention that some of these phrases may well change:
18:40 < ocharles> Muz: nikki has just done some work rewriting them, but we can probably easily stick an UPDATE btrim at the end of that update process

So, when this does happen, a delta for cleaning this data up would be a prime opportunity for amending this.