A family of Microsoft word processing software products for creating web, email, and print documents.
There is a file named MSO0127. In this case the number doesn't correspond to a language ID; the file contains the Math AutoCorrect entries used in the Insert > Equation feature.
The AutoCorrect.dotm file is a template, but it contains only the instructions in the body text and the code that runs the backup and restore. It isn't intended to be the base for a document. The code creates the AutoCorrect Backup document as a separate file, based on the Normal.dotm template.
If you add formatted entries with a specific proofing language to the list in the AutoCorrect dialog, those entries are stored in the Normal.dotm template. The proofing language is saved as part of the value's formatting. That restored entry will be autocorrected only if the proofing language at the insertion point matches the entry's proofing language.