Common uses.
If you do signings in jails, the inmates never have any photo-identification. They only have a wristband which you can not use as notary identification. Relatives or the attorney of the inmate may have the inmate's ID and bring it. But, if they don't, you have to rely on credible witnesses. Elderly people often have expired identification, so for them, you will commonly need credible witnesses. People who changed their name, but didn't change the name on their identification are candidates for using credible witnesses.