Courses created with Social Format include the following strings that appear to ignore language settings:

• "Social forum"
• "An open forum for chatting about anything you want to"

This is theme independent (I have only tested with Boost and Adaptable) and, just to make things harder, neither have debugstringids when rendered in my setup:

• https://dni-school-campus.com/mod/forum/view.php?id=10
• https://dni-school-campus.com/course/view.php?id=5 (this view only contains the second string)

Both appear (translated) in language packs associated with the following ids:

• namesocial (mod_forum component)
• introsocial (mod_forum component)

This sort of behaviour my also appear in other types of forum but I haven't tested them.