If you are using Confluence Data Center and your administrator has temporarily switched your instance to Data Center Read-only mode, you may notice changes to the behaviour of Community Forums. These behaviours are displayed only while your instance is in read-only mode.
Make Sticky option is hidden
Lock Topic and Mark/Unmark as Topic are hidden
Sticky Topics On Top checkbox is disabled
Create Forum menu item is hidden
Onboarding pop-up dialogs are not displayed
Remember that you cannot edit or create Confluence pages in read-only mode.
See Atlassian’s Using Read-only Mode for Site Maintenance to learn more about general Confluence use in Data Center read-only mode.