Sometimes when sharing documents reviewers may forget to record the changes they make. This is not a problem with Calc. If a reviewer edits a spreadsheet but forgets to record the changes, Calc can find the changes if you compare documents.
In order to compare documents you need to have the original document and the one that is edited. To compare them:
Open the edited document that you want to compare with the original document.
Select Edit > Compare Document (Figure 113).
An open document dialog appears. Select the original document and click Insert.
Calc finds and marks the changes as follows:
All data that occurs in the edited document but not in the original is identified as inserted.
All data that is in your original document but is not in the edited document is identified as deleted.
All data that is changed, is marked as changed.
From this point you can go through and accept or reject changes as you could normally.