| Subject | English | Welsh |
| comp., MS | backward compatibility | cydnawsedd am yn ôl (The capability of source code or programs developed on a more advanced system or compiler version to be executed or compiled by a less advanced (older) version) |
| comp., MS | Compatibility Checker | Gwirydd Cydnawsedd (A feature that identifies elements in your file that aren't supported or will behave differently in a different format or previous version of the product) |
| comp., MS | compatibility mode | modd cydnawsedd (A feature of a computer or operating system that allows it to run programs written for a different system) |
| comp., MS | Compatibility View | Gwedd Cydnawsedd (A view mode in Internet Explorer that determines whether content is rendered as if users were viewing it in a previous version of Internet Explorer) |
| comp., MS | Office compatibility definition file | Ffeil diffiniadau cydnawsedd Office (A file that stores information about compatibility issues and workarounds and makes it available to the Office Telemetry Log and Office Telemetry Dashboard) |
| comp., MS | Program Compatibility troubleshooter | Datryswr Problemau Cydnawsedd Rhaglenni (An easy-to-use troubleshooter that helps find and fix program compatibility issues) |
| comp., MS | Windows Installation Compatibility Advisor | Ymgynghorydd Cydweddoldeb Gosod Windows (A downloadable Web application that helps Windows users identify which edition of Windows meets their needs, whether their PCs are ready for an upgrade to the next Windows version, and which features of the suggested Windows version will be able to run on their PCs) |