-This directory contains documentation files that are processed in some way in
-order to make the documentation files that form part of Exim distributions. A
-non-standard document processor is currently in use (October 2004), but in the
-long term something more standard will have to take over.
+This directory contains documentation files that are processed in some way in
+order to make the documentation files that form part of Exim distributions. A
+non-standard document processor (SGCAL) was used up to and including release
+4.50 of Exim to process the sources for the manual and filter docuement.
+Subsequent documentation releases operate using DocBook input, so these files
+are now historical relics. The FAQ source is still (June 2005) current, but may
+be superseded in due course.
+
+The filter and spec source files have now been removed from here to
+prevent further confusion.