VS 2022: https://marketplace.visualstudio.com/items?itemName=NikolayBelyh.IdMsoAutocompletevs2022
VS 2019: https://marketplace.visualstudio.com/items?itemName=NikolayBelyh.IdMsoAutocompletevs2019
VS 2017: https://marketplace.visualstudio.com/items?itemName=NikolayBelyh.IdMsoAutocompletevs2017
VS 2013: https://marketplace.visualstudio.com/items?itemName=NikolayBelyh.IdMsoAutocompletevs2013
The extension provides autocomplete for CustomUI for office ribbon (means, auto-complete for the built-in item identifiers, like idMso, insertBeforeMso, insertAfterMso and imageMso).
Extension supports all office applications and is enabled by opening XML file in the Visual Studio editor, which belongs to customUI namespace, i.e. "http://schemas.microsoft.com/office/2009/07/customui" or previous version.
The extension is based on the published Microsoft files, and includes the microsoft idMso database and msoImage database. Office 2010, 2013 and 2016 are supported.
Preview:
Because this extension is using private assembly for XML parsing, had to do a version-per-visual-studio version