| Subject | English | Welsh |
| comp., MS | check box | blwch ticio (" A control that indicates whether or not an option is selected. A check mark or "x" appears in the box when the option is selected.") |
| comp., MS | check in | rhoi nôl (To place a file or project back in a source repository. This releases the lock for editing and enables other users to view the updated file or check out the file) |
| comp., MS | check mark | tic (A small x or other sign that appears in the check box if the option represented by the box is selected) |
| comp., MS | Check Names | Gwirio Enwau (A button on the message toolbar that compares the names in the To, Cc, and Bcc boxes against the names in the Address Book and against those contact folders that you've specified as Outlook Address Books) |
| comp., MS | check out | tynnu allan (To retrieve a writable copy of a file or project from a source repository. This locks the file for editing to prevent others from overwriting or editing it inadvertently) |
