You know the one I mean, Tμν.1 Is it the stress-energy tensor, or the energy-momentum tensor? This is for the purposes of tags, where having both is redundant. This was brought up in chat, and there is a proposal on our little-visited tag synonyms page. However, it was pointed out there that the idea of just combining everything into stress-energy-momentum-tensor won't work due to character limits.
Moreover, I dare anyone to claim with a straight face that they would actually say "stress-energy-momentum tensor" in conversation.
I therefore propose that one of stress-energy-tensor or energy-momentum-tensor be taken to be "standard," with the other made a synonym. My understanding is that either tag can then be applied, with the synonym silently being replaced, no harm done, no retagging effort necessary.
Rather than proposing a synonym on my own, only to have no one look at that page anyway,2 I figure this proposal should get some community consensus as to which way the replacement should go. I personally grew up learning that "stress-energy" was a tensor and "energy-momentum" was a 4-vector, but perhaps I'm in the minority, or perhaps there's good reason to differentiate as much as possible the stress-energy tensor of relativity from the stress tensor of mechanics.
Vote below as you see appropriate, or add your own original thoughts in another answer.
1 Yes, I am fully aware that string of symbols refers to an unspecified component of a tensor, and not an actual tensor. Mathematically precise people, please don't hurt me. Everyone else, I still reserve the right to admonish you for conflating these two things :P
2 There are plenty of other suggestions there - interested users should vote on them!