{remove '1..10', prime} runs a sequence in remove mode: every value that belongs to the named type is dropped, the rest stay - here 1 4 6 8 9 10. It is the same run as {sequence '1..10', remove, prime}, and the exact inverse of {keep}: together the two split a list in two.

Without a range the candidates run from from (default 1) upward, and rows counts what is left: {remove prime, rows=5} is the first five numbers that are not prime, 1 4 6 8 9. A stored sequence, named bare, works as the source as well, and the prefix form {remove:odd rows=5} names the type in the tag.

To invert an action - all but the first three - use the negative option of {sequence} instead; remove is the inversion for plays.