doc: design_www: document offline friendliness

This isn't anything new and has been a part of the design
since the beginning, but it may not be apparent to some
folks.

diff --git a/Documentation/design_www.txt b/Documentation/design_www.txt
index 240fa5046b35bc12a3dad7aca7d567d376e6a609..b1f916ddb3697606aaf623ada2ef3b607666e6f3 100644 (file)
--- a/Documentation/design_www.txt
+++ b/Documentation/design_www.txt
@@ -77,6 +77,23 @@ installed to render uncommon characters.
 Plain text (raw message) endpoints display in the original encoding(s)
 of the original email.
 
 Plain text (raw message) endpoints display in the original encoding(s)
 of the original email.
 

+Offline friendly
+----------------
+
+The "/t/", "/T/", "t.mbox.gz" endpoints are designed to be
+useful for reading long threads for users with intermittent
+connections or saved for offline viewing.
+
+Date displays are always absolute, not the "X hours ago"
+pattern commonly seen because readers may be reading a
+previously-saved or cached copy.
+
+HTML URLs end with '/' or "$FILENAME.html".  The reason many
+URLs end with the '/' character is so it can trivially be saved
+to a directory via wget or similar tools as "index.html", making
+it easy to mirror all files ending in ".html" using any static
+web server.
+

 Guidelines for using limited HTML
 ---------------------------------
 
 Guidelines for using limited HTML
 ---------------------------------