.MXLIFF files are Phrase specific files based on XLIFF 1.2. The core of the file is XML and is designed for localization tools. They hold both source and target information when exported from a job.
Timestamping of .MXLIFF files follow the Unix format. They can be converted using this online utility: unixtimestamp.com.
.MXLIFFs are primarily intended for translation inside the CAT editor or to be directly imported via the UI and can be downloaded from the editor from the menu.
If unable to download an .MXLIFF file from the CAT Desktop Editor or the CAT Web Editor, the ability to do so may have been restricted by a project manager. Reach out to the point of contact in the organization for more information and ask to have this option enabled.
Once finished processing in the desktop editor or other tools, .MXLIFF files can be imported via Tools > Upload.... Multiple or large .MXLIFF files may be imported in a single .ZIP file for convenience and a quicker upload.
When translating .MXLIFF files outside of Phrase, it cannot be guaranteed how the files will be processed by other software.
.MXLIFF files are only supported in SLD Trados from version Trados Studio 2021. .MXLIFF files are not automatically recognized by older versions of SDL Trados and are only imported as reference documents. To import an .MXLIFF file into SDL Trados as a translatable file, the extension must be changed to .XLIFF.
SDL Trados adds additional information to .XLIFFs that are not a native part of the .MXLIFF file format. Select the Preserve; don't add if not originally present BOM option and the Do not store segmentation information in the translated file setting when exporting from SDL Trados to produce a file that be used with Phrase.
.MXLIFF files are supported in memoQ 10.0. If working with older versions, see Marek Pawelec's blog post for current instructions.