The buffer of the `sticky summary' does not killed by typing q.
Sticky buffer is created by entering the summary by typing C-u g
or type M-s (wl-summary-stick) on the normal summary.
The buffer name of the sticky summary becomes like `Summary:folder-name'.
You can visit the sticky summary at any time by C-x b
(switch-to-buffer). To exit sticky summary, type C-u
q. Other operations in the sticky summary are same as normal summary.
wl-summary-always-sticky-folder-list specifies the folders that
are automatically stuck.
Go to the first, previous, next, last section, table of contents.