Remember, Microspeak is not necessarily jargon exclusive to Microsoft, but it’s jargon that you need to know if you work at Microsoft.

You may receive an email message that was sent to large group of people, and it will say something like “Little-r me if you have any questions.” What is a little-r?

The term “little-r”¹ (also spelled “little ‘r'” or other variations on the same) means to reply only to the sender, rather than replying to everyone (“reply all”). My understanding is that this term is popular outside Microsoft as well as within it.

As I noted some time ago, employees in the early days of electronic mail at Microsoft used a serial terminal that was connected to their Xenix email server, and they used the classic Unix “mail” program to read their email. In that program, the command to reply only to the email sender was (and still is) a lowercase “r”. The command to reply to everyone is a capital “R”. And the “little-r” / “big-R” commands were carried forward into the WZMAIL program that most employees used as a front end to their Xenix mail server.

These keyboard shortcuts still linger in Outlook, where Ctrl+R replies to the sender and Ctrl+Shift+R replies to all. If you pretend that the Ctrl key isn’t involved, this is just the old “little-r” and “big-R”.

Related reading: Why does Outlook map Ctrl+F to Forward instead of Find, like all right-thinking programs? Another case of keyboard shortcut preservation.

¹ Note that this is pronounced “little R”, and not “littler”.