The name of the site is still only Latin, and I see that our main topic is and will be Latin.
Some other languages are included on the side.
Greek is special.
It is so closely related to Latin, that it made sense to include it at our site.
We have discussed the matter extensively under the meta tag greek, and we concluded that Greek is allowed, but only up to the end of classical antiquity and excluding New Testament Greek.
(I have a feeling that we might expand to include New Testament Greek at some point, but that should not be discussed here.)
The crucial restriction is that modern Greek is not allowed.
Older forms of Greek had a lot of interaction with Latin, and knowing the basics of Greek is useful for understanding Latin deeply.
There is a similar cultural connection with Etruscan, so it makes sense to allow questions about etruscan.
Small languages closely related to Latin are also allowed.
They are small and will not produce a flood of questions (or their own SE site), and anyone who studies them is extremely likely to be knowledgeable in Latin as well.
This reasoning includes Oscan, Faliscan, and Umbrian.
(Do I forget something?)
So, we allow questions about any of these languages:
Latin, Greek, Etruscan, Oscan, Faliscan, Umbrian.
You can ask about Faliscan without any connection to the Latin language.
Any language whatsoever can be discussed in a question, but if it's not on the above list (or approved at meta), the question has to relate to one of the listed languages.
For example, translation questions from French to Latin are on-topic, but questions about French only are off-topic.
Other classical languages like Arabic, Hebrew and Sanskrit are off-topic.
(Of course, their relations to Latin are a welcome topic.)
Their connection to Latin is narrower and a somewhat different subset of people study them.
Some of the cultural connection between Latin, Greek and Etruscan is in the way we study languages in the modern world, but much of the connection is ancient.