Just Enough Professions (JEP)

This mod enhances JEI functionality by adding useful information about villager professions. Now you can easily determine which workstations are required for each villager profession.

To use the new feature, simply press the usage view key in JEI (default U) on an emerald or villager spawn egg. A complete list of all available professions will appear on screen. If you need to know which specific mod added a particular profession, just hold the Shift key - in this case, the mod identifier will be displayed before the profession name.

For REI users, there is a similar mod called Roughly Enough Professions (REP).