Replicon's Reports Field Matrix is a spreadsheet that shows all report fields (or columns) available in Replicon, alongside the report templates they're available in. It also shows which filters are available in each report template.
This document is useful if you're looking for a particular field to report on, or if you want to compare report templates. Excel's sorting functionality can be useful when comparing reports.
In the Reports Field Matrix, reports are listed by report template, not by default report.