GitLab

 (Store custom flags and keywords): Mention `gnus-registry-user-format-function-M' and `gnus-registry-user-format-function-M2'.
gnus-registry.el (gnus-registry-user-format-function-M): Use `mapconcat'.
 (gnus-registry-user-format-function-M2): Use to see the full text of the marks.  Make "," the mark text separator.