Gedole HaDor: who and how
The phrase "Gedolim" or "Gadol haDor" has appeared in several questions and answers on this site (see here, here, here, and here). However, the definition of "Gadol" is unclear. (Most of these questions have been closed due to this exact issue.)
How does a rabbi become a "Gadol?"
- Who decides?
- Are there any specific requirements?