I've asked for this before. There are a number of things TLA's you can't search for. ELS yup. CNC. .. there are more too.... Josh had other more important things to fix. @Dabbler do you know how this problem was addressed on HM? there is another one you can't search for HM.
I've looked quite deeply into xenforo, and cannot figure why it will search for the letter "B" successfully on the HM forum (it finds "B & S Grinder", for instance) I'll try again fresh tomorrow.... There has to be a reason.... it is driving me bonkers!
But we also need to be mindful of the server load. Searching the forum using its own server is a potentially onerous process task - more and more so as the search terms get smaller. Expediting searches by creating on-going indexes is also onerous. Google and the other search engines do it as an integral part of their business raison d'etre. Our server doesn't. Routinely asking the server for short phrase searches might be more than we should ask of it. I think we should let Josh decide that.
In the meantime, using the Google site search has no server overhead and the quotes method is onerous enough that it wont get used very often.
I'm not personally fussed about it. I can get what I want when I need it. It's just too bad I don't have @YYCHM 's memory..... LOL!