Feature summary
If the {{int:}} parser function is accessing a system message that does not exist a tracking category shall be issued.

• The same goes for Lua.
• The message identifier appears in ⧼ ⧽ brackets which is available to visual inspection only.

Lua for any attempt to access content but :exists() or :isBlank() or :isDisabled().

Use case(s)
When a page or other system message is using a system message, but this is removed or renamed later for any reason, that cannot be discovered.

• If the identifier is misspelled but not noticed on publishing, this cannot be tracked.

Benefits
Many project pages, help pages documenting functionality and last but not least other system messages use {{int:}} to ensure that the current wording used in the interface is displayed synchroneously as guidance.

• If such a message vanished, replaced by other organization, the broken page cannot be identified.
• Maintenance staff should be able to watch the tracking category and identify pages which need to get updated. Similar to MissingTemplates.