Users can create queries and export the results in Microsoft Excel format. However, some users have experienced two additional fields displaying in the .xlxs output file which were not a part of the query output criteria. These two fields are Rev/Base Currency ID and QueryRec ID.
Currently, our Excel writer does not respect the "IsHidden" tag for additional fields in query output. At this time, CRM will continue to show all hidden fields, as some users may rely on these hidden columns to be included in the query output.