An anonymous editor at en.wp reports:
"I was attempting to correct a minor error at [[Class 455]]. Although I was only attempting to change one word, the editor changed,
:...in common with the Classes 313 / 314 / 315 / 507 / 508 units."
:<nowiki>...in common with the Classes <a href=tel:313 / 314 / 315">313 / 314 / 315</a> / 507 / 508 units.</nowiki>
and then complains of a formatting error and refuses to allow the change to be saved. The editor seems to be interpreting the list of class numbers as a telephone number."
I have been unable to reproduce this using Firefox 22 on Linux, including editing the article in question.