As Cerberus mentions in this answer:
With many (semi-)deponent verbs, the perfect participle often has a present meaning.
And in the comments:
I thought this was commonly known, but apparently not.
Indeed, I had not known about this at all!
How common is this usage? Are there any restrictions on it, such as only appearing as a participle (not as a finite periphrastic form with esse), or not appearing in conjunction with morphologically-present verbs? And what sort of aspect does it have?