What counts as a ping? [duplicate]

Question

On desktop SE, I can type @ and the usernames that I can ping will be suggested. It's known that pinging the OP as the only commenter, or pinging the author of an answer as the only commenter, will strip the @ping.

On mobile SE, it is not really possible to ping a user in comments, which is very annoying to me since I way prefer the mobile site over the mobile app.

However, a few times in the past few days I have tried to ping a commenter from the mobile site, just by typing their name. For instance, if the user's name is RikerW, I typed @rikerw blah blah.

Those pings didn't get replies from active users. We also know that @pings are just text, not special entities like on Facebook, which is why they are not updated with usernames. (see Change all @username references in comments when a user changes their name?)

What causes a ping? How do comment @replies work? says "reasonable match", but what is that?

• Must I type the @ and select one of the options with TAB, or
• can I just type the user's name?
• Does case matter?
• Is it possible to ping from the mobile site?

Answer 1

To ping a user you should start with @. For my name @pat is sufficient.

So:

• Always start with the @ symbol;
• Names are not matched case sensitive. No leave out spaces though;
• You don't need the full name or use the tab key to 'select' a name, three letters are enough to ping a user;
• It does work perfectly from the mobile site, it just lacks auto-complete on the name.