Prof. choice pocket cam?

As a previous 35mm SLR user, I was aware that professional
photographers regarded several specific models of camera as worthy
pocket-size backups. For example, the Ya****ca T4.

Along these lines, what models are pro digital photographers tending
to carry these days as a backup pocket camera?

By "pocket" I mean something that can be carried relatively
inconspicuously in a pants pocket.

Thank you for any advice.

Mike Kendall