I half-disagree with Ubiquitous on this one. I mentioned in a comment to another meta-question, that we should use the primary JEL codes. I have started to think that we should go for the second-level, like this
-first the name and then the code, for search purposes.
No system is perfect, and as in research papers, askers will use more than one tag. The benefits of having in place a taxonomy used globally (and characterized by a certain degree of consistency) far outweigh the occasional problems.
Do we really think that letting people creating tags without guidance will result in something more useful? I am not saying "ban everything else", just "let's create them so that the askers find them, and see what happens".
Of course one could think "why not use just the nomenclature and leave the codes out?" I would answer "for search and educational purposes" but also, for the academic flavor.
How are we going to decide this? If decided, I am volunteering to create all the tags.
Responding to questions in the comments by user @Foobar:
"Academic Flavor": the official motto of this site is "For professional and academic economists and analysts ". And we do want for this to hold. Using the JEL classification with the code, is a way to signal that this place is indeed for academics and professionals, in an immediate and unmistakable way. This shapes expectations, and affects the way newcomers will view the content here: it helps the chances that instead of, say, concluding "this is not truly a place for academics and professionals -goodbye" they will think "this is not yet a place for academics and professionals -let's contribute in making it one".
"Search benefits" This a) pertains to the use of the words that the JEL classification uses, and I don't see why we should not have them here, but also, to the codes themselves, since in my experience, academics and professionals search also using JEL codes to focus the search.
"Educational Purpose:" The taxonomy of every discipline is a core part of it, since it reflects the way it partitions the phenomena that it studies. And the JEL classification is globally used. Bringing the non-academic users here (and there will be many of them), and even the economics students, in contact with this taxonomy, name and code together, has an educational effectsince it helps them get familiar with the classification, and know that this is indeed the classifiataion used in the discipline.