Document how users can have a custom identifier without "T" in it

README.org

@@ -2791,6 +2791,43 @@ Slightly modified version of `denote-generate-identifier-as-date'."
             (my-denote-format-date (or date (current-time))))))))
 #+end_src
 
+*** A custom identifier without the time separator
+:PROPERTIES:
+:CUSTOM_ID: h:d238cd1f-a185-4dbe-a9f3-0dea29273e1f
+:END:
+
+The default Denote identifier consists of the date as =YYYYMMDD=, then
+the letter =T=, and then the time as =HHMMSS=. Users who do not want
+the letter =T= there can use the following:
+
+#+begin_src emacs-lisp
+(setq denote-get-identifier-function #'my-denote-generate-identifier-without-time-separator)
+
+(defconst my-denote-date-identifier-format-without-time-separator
+  (replace-regexp-in-string "T" "" denote-date-identifier-format))
+
+(defun my-denote-generate-identifier-without-time-separator (initial-identifier date)
+  "Generate an identifier based on DATE.
+
+If INITIAL-IDENTIFIER is not already used, return it.  Else, if it is
+possible to derive an identifier from it, return this identifier.
+
+Else, use the DATE.  If it is nil, use `current-time'.
+
+Slightly modified version of `denote-generate-identifier-as-date'."
+  (let ((denote-used-identifiers (or denote-used-identifiers (denote--get-all-used-ids))))
+    (cond ((and initial-identifier
+                (not (gethash initial-identifier denote-used-identifiers)))
+           initial-identifier)
+          ((and initial-identifier
+                (string-match-p denote-date-identifier-regexp initial-identifier)
+                (date-to-time initial-identifier))
+           (denote--find-first-unused-id-as-date initial-identifier))
+          (t
+           (denote--find-first-unused-id-as-date
+            (format-time-string my-denote-date-identifier-format-without-time-separator (or date (current-time))))))))
+#+end_src
+
 *** A custom identifier to encode publisher data
 :PROPERTIES:
 :CUSTOM_ID: h:f92cd454-51f4-4403-9061-3b2efaef2851