We might call these my brown M&Ms. Van Halen stipulated in their riders to tour contracts a bowl of M&Ms without the brown ones. This has often been taken to be typical rock-band high-maintenance narcissistic self-regard and self-indulgence, but this clause actually served a deeper purpose, serving as a marker of attention to detail:
If brown M&M's were in the backstage candy bowl, Van Halen surmised that more important aspects of a performance--lighting, staging, security, ticketing--may have been botched by an inattentive promoter.
If students use the word "importante," if they haven't put a title on their paper, if they use the "time immemorial" beginning, then I know they haven't been paying attention to my very explicit oral and written instructions. Sure, an otherwise good paper might use the word importante in every other sentence, but usually this means that the student will also not apply recently reviewed grammar points in revising their writing. They will probably use the passive voice in a paper a week after I told them simply not to use the passive voice at all in Spanish.
Of course, the consequence of messing up a Van Halen concert might be very serious: death, if a stage collapses because a promoter has not paid attention to how much weight it has to support. The consequence of brown M&Ms is less severe. In writing, the consequence of messing up the small things is that the reader will lose faith that the writer is to be trusted in the communication of scholarly knowledge.