Ask HN: Can I declare varchar like this in an SQL Column?

Hey,

I may be totally wrong here because i'm only a junior and not too sure but I was certain that the maximum varchar() that could be set was 255 varchar(255).

However, i'm working on a database at the moment which was developed by another team and they have varchar(9999).

Is that right? I have had a quick Google but can't find it.

Cheers for advice in advance folks :)