Incidental

His criticism only referred to incidental matters.

My activities on the Web are mainly for self-promotion. It's not really a public service, as the audience is merely incidental and I might be solipsistic. It's a window for vanity with the aim of promoting my own hobbies. If there's an audience, then fine, but if none, then fine, too. If you think that the information is helpful or entertaining, then "it's good for you."

It is of the highest importance in the art of detection to be able to recognize, out of a number of facts, which are incidental and which vital.

Having gathered these facts, Watson, I smoked several pipes over them, trying to separate those which were crucial from others which were merely incidental.

That character, though colorful, is incidental to the overall plot.

incidental evidence

Injuries are incidental to contact sports: they're going to happen.

She's costing us a lot in incidentals.