OrangeSurf on Nostr: Next we have standard transactions, which are the transactions permitted into the ...

Next we have standard transactions, which are the transactions permitted into the mempool of a node according to it's policy rules.

The default policy rules which come packaged with the latest bitcoin core release are generally adopted by the network within a year. Each release with new policy rules will result in different set of standard transactions, so it's a moving target, but on any given node the rules are set at any given time.

Each node can configure it's policy rules as it sees fit (in theory, more on this later) and transactions must first pass consensus rules before considering policy. This means that there is no risk that using different policy rules will break consensus. Another way to say this is that standard transactions are a subset of valid transactions.