$mod?A: The purpose of 
$mod discord command is to help moderators of a given tribe find post that fit a certain criteria and moderate them. Once moderated, they are removed from the report so that a new list of posts can be moderated.
Example query:
The main thing we're looking for is off-topic, low-effort posts that try any and all tribe tags, just to randomly earn rewards. But the side-effect is to widen curation exposure.
A: Each time the $mod command is used, it is limited to five results. This is because the background job takes time to run, as it is fairly resource-intensive.
A: The default is to find posts that are less than seven days old (thus votable), that also have more than five tribe tags (perhaps spammy), and a pending payout of at least 1.000 of whatever token being queried for.
A: As far as
For example, here are the lists for several popular tribes, have a look:
However, if you are not in the top twenty, you can still influence the list by downvotes, if your downvote removes enough rewards to bring the payout below the default threshold (1.000 of the token being moderated). The top twenty can remove posts from the $mod results by upvote at any weght (+1% through +100%).
In a sense, a 1% upvote by a moderator is like saying "Ok, I have moderated this, show me something else."
A: Perhaps someone has fully moderated the tribe you're querying on. This can happen if moderators have upvoted all of the posts that would have been in the result, for the default criteria. Try alternate criteria.
For example, PAL is often fully moderated by default because there are a lot of active curation by the top influencers for that tribe:
Instead of taking the default of 5 tags, try 4 or less, lower the rewards, or both:
A: For certain tribes, due to posting volume and high levels of moderation, the report may take several minutes to find 5 qualified posts. This is often the case for general purpose tribes like PAL that already have high moderation. But due to the nature of this command, it's not really a good fit for general purpose tribes anyway. Maybe try a more focused tribe like SPT.
See: Command: $mod