Hi, thanks for responding. I had to change his password as his iOS tablet and phone had logged out of Moodle and wouldn't permit him to log back in with the same password he is using without a problem on a Microsoft desktop. I also use Moodle mobile on my Android phone and tablet without any problems and I don't have the same line instruction in my personal User account.
I've just looked at the Moodle Mobile settings and I can find mention of iOS, but I don't understand enough about it to know what this means!
Fiona