}
/**
- * does the string match an anonymous IPv4 address?
+ * Does the string match an anonymous IPv4 address?
*
- * Note: We match \d{1,3}\.\d{1,3}\.\d{1,3}\.xxx as an anonymous IP
+ * This function exists for username validation, in order to reject
+ * usernames which are similar in form to IP addresses. Strings such
+ * as 300.300.300.300 will return true because it looks like an IP
+ * address, despite not being strictly valid.
+ *
+ * We match \d{1,3}\.\d{1,3}\.\d{1,3}\.xxx as an anonymous IP
* address because the usemod software would "cloak" anonymous IP
* addresses like this, if we allowed accounts like this to be created
* new users could get the old edits of these anonymous users.