I have been looking at tags and synonyms lately (can you tell?).
While the tags stationery and stationary may sound the same, they have very different meanings. Currently, stationary (which means not moving) is a synonmym to stationery (which means related to paper products).
I saw where the tags were made synonyms due to user confusion. I think this might lead to more confusion, especially by people who know the difference.
If the tags are split, we (or I) should update the description to match the definitions.