You set up for example an analysis view for the department dimension. You post several purchase invoices with different departments on multiple G/L accounts. You also post several purchase invoices with no department dimension on the same and different G/L accounts Then you open the analysis by dimension request page and choose to see G/L accounts as rows and department dimension values as columns. You hit the show matrix button. Now you see a lot of lines with all possible G/L accounts (if you added a filter, only those G/L accounts are shown). But the problem is that you also see the G/L accounts (records) with no amounts posted with department dimension. This makes it difficult for the user to scroll trough all lines.
This is one example of the possible analysis by dimension matrix views, but other combinations of lines and columns are also possible. In all these combinations, it would be helpful to have a parameter (maybe on the analysis by dimension request page) where you can setup that you do not want to see rows with no value and/or columns with no value. If this parameter is set to true, a much cleaner version of the matrix will be shown which is easier for the end user to scroll through.