Shows the instances of a block in a course.
SHOW BLOCK <blocktype> IN <courseidentifier> SHOW BLOCK <blockidentifier> (todo)
SHOW BLOCK latest_news IN idnumber:U345654
SHOW BLOCK idnumber:"B203_52"
SHOW BLOCK current
None
(*) This assumes the “block identifiers” provided by the installation of certain third-party plugins are in place.