OP_RETURN outputs
outputs that carry data instead of money
How many outputs in this block exist to carry data rather than to hold bitcoin. They can never be spent, so they are the deliberate way to write something into the chain.
DefinitionCount of OP_RETURN outputs in the block.
LimitIt is almost identical to the count of transactions carrying an OP_RETURN (r = 1.0000), because nearly every such transaction carries exactly one.