As I understand it* (and focused on a first impression of your work):
"E" ("no adult themes including alcohol, tobacco, drugs or fetishes")
Basically everything you couldn't discuss in front of a child that's old enough to find and navigate NG on the internet.
"T" ("mild mature themes")
Bikinis, underwear, discussing mortality, the kind of violence that only produces a few drops of blood...
"M" ("mature themes")
In a nutshell: "Adult stuff" that, if you did that 'to' a minor could likely spell jail time - but doing it 'in front of' a minor would only get you "into trouble".
(Plus the kind of violence that paints a room red.)
"A" ("Nudity, sex, skintight or see-through outfits that leave nothing to the imagination, extreme gore, fetishes, extreme adult themes.")
I hope that helps, but in doubt you can always contact a moderator for a more binding answer:
https://www.newgrounds.com/wiki/help-information/site-moderation
* based on this: https://www.newgrounds.com/wiki/help-information/terms-of-use/art-guidelines
RachelLately
Taxes?! Made me laugh.
MalachytePanda
Ha ha, glad to hear!