--- a/doc/TIFFS-Overview	Sat Dec 31 09:27:01 2022 +0000
+++ b/doc/TIFFS-Overview	Sat Dec 31 21:08:05 2022 +0000
@@ -237,6 +237,25 @@
 no different in this regard; for the implementation details, read the source
 code.
 
+TIFFS filename and pathname limits
+==================================
+
+Classic TIFFS, as in the canonical firmware source from TI, imposes the
+following limits on the content written into FFS:
+
+* Each elementary filename or pathname component (the name of each individual
+  file or subdirectory within its parent directory) is limited to 20 characters;
+
+* The set of allowed characters in these elementary filenames is limited to
+  [A-Za-z0-9_.,+%$#-];
+
+* The maximum pathname depth is limited to 6.
+
+As an illustration of the pathname depth limit, the deepest allowed path to a
+non-directory file is /d1/d2/d3/d4/d5/file.  It is also possible to have a
+directory nesting of /d1/d2/d3/d4/d5/d6, but in this case the deepest directory
+can only be empty.
+
 How this FFS comes into being
 =============================