Currently, we have a "tag triangle": charity sadaqah zakat. This was raised in 2012 here: List of tag synonyms and tags to be burninated or removed
In this situation, we have:
Questions pertaining to "sadaqah" which don't pertain to "zakat". E.g. Should we give money to street beggar?
Questions pertaining to "zakat" which don't pertain to "sadaqah". E.g. Can someone give zakat to his unmarried (and young) brother?
Every question pertaining to either "sadaqah" or "zakat" also pertains to "charity".
The Arabic "sadaqah" and "zakat" are more specific and technical, in keeping with:
Using the proper vernacular is an important part of setting the right tone for the site. Certainly, questions involving simpler concepts are welcome, but you should not be targeting and reaching out to "curious onlookers" specifically. -- Robert Cartaino ♦
This leads me to propose: let's get rid of the charity tag.
Ordinarily, questions which pertain to "charity" can be instead tagged "sadaqah" and/or "zakat". While it seems plausible that a question may pertain to "charity" without pertaining to "sadaqah" nor "zakat", it seems unlikely (and we have to trade it off with the alternative, i.e., retaining the tag triangle).
14 12 questions currently tagged charity. Of these:
(An alternative would be to use "charity" and get rid of "sadaqah" and "zakat", but points 1. and 2. above suggest this distinction is useful.)