Can you create Numeric Tags?

Hello:

I’m trying to add numeric tags to a note - e.g. #2020 - to denote the year that something was released, but Obsidian does not seem to treat that as a tag. Is there a way to accomplish this via an escape character or some other means?

Thanks in advance for your help.

Purely numeric tags are not supported.

Start with an underscore?
#_2020

Is that supported?