A check that's been enabled for years on Stack Overflow attempts to identify unformatted code in posts (questions and answers) from new users, and blocks posting until it has been corrected. A related feature checks the ratio of formatted lines of code to non-code characters in questions.
As of right now, both of these checks are enabled here too.
Rationale
The recently-revised scope for this site makes it abundantly clear that debugging code-dumps is not on-topic here:
Therefore, I think it's reasonable to expect folks who are posting code in their questions to include ample explanation along with it - ideally, code would be illustrative of some concept, not a literal dump from some program they're working on.
In practice, this shouldn't affect very many questions; my spot-checks indicate only a few recent instances where either of these would've blocked someone from posting, and all of them are already deleted because they were blatantly off-topic anyway.
But please let me know if these checks cause any issues.