If you open a document that is showing, you can convert it to the format of your current Word version. However, if you understand what it means, you can better decide whether you want or need to update the document to get out of Compatibility Mode. In many cases, you can just ignore the information about Compatibility Mode. Also, a document in Compatibility Mode preserves the layout of the document from the earlier version. This means that the document can still be edited by people who are using the earlier version of Word. As long as a document is showing, new or changed Word features that were not included in the earlier version will be disabled.