I've always been partial to "irrelevant to the discussion".
For example: if a post is detailing increased temperatures compared to a previous year:
✅ Comment saying "This is most likely an effect of global warming"
✅ Comment saying "This paper is potentially biased as the paper/publication is sponsored"
✅ Replies to these comments discussing the legitimacy of their claims (for or against them)
⛔ Comment which is promoting their own content (even if related) with no discussion of the linked post
⛔ Intentionally incendiary comments. "Liberals will say it's climate change I bet."
⛔ Completely off topic. "Ok but guys let's talk about SCARING THE HOES for a second here. Straight flames."
Too many people use a downvote as "I disagree" when a comment may actually provide a different viewpoint and - as long as it's respectful and open to counterpoints itself - can be a nice addition to the discussion.