TL;DR
As a continuation to efforts of setting the functional tags right (see here for background and more info) we need to gather community consensus on what the scope of esters should be.
Since esters has now been created I set about writing a tag wiki for it. I have only included carboxylate esters in the scope of the tag but @Loong pointed out that there are other types of esters (orthoesters as well as many inorganic ones - phosphate, chromate to name a few) as well. Should these be included in the scope of the tag? The vast majority of esters questions are about carboxylate esters but I guess we could include other types as well.