These are defined in constants.rb.
Satoshi is the smallest unit representable in Bitcoin transactions.
One bitcoin equals 100 million satoshis.
1 bit is 100 satoshis (1 millionth of a bitcoin).
Changing these will result in incompatibility with other nodes.
The maximum allowed size for a serialized block, in bytes.
The maximum allowed number of signature check operations in a block.
No amount larger than this (in satoshis) is valid.
Coinbase transaction outputs can only be spent after this number of new blocks.
Threshold for BTC::Transaction#lock_time: below this value it is interpreted as a block number, otherwise as UNIX timestamp.
P2SH BIP16 didn't become active until April 1, 2012. All transactions before this timestamp should not be verified with P2SH rule.
Scripts longer than 10K bytes are invalid.
Maximum number of bytes per "pushdata" opcode.
Number of public keys allowed for OP_CHECKMULTISIG.
Maximum number of operations allowed per script (excluding pushdata operations and OP_N). Multisig operation additionally increases count by a number of pubkeys.
Can bend these without becoming incompatible with everyone.
The maximum number of entries in an 'inv' protocol message.
The maximum size for mined blocks.
The maximum size for transactions we're willing to relay/mine.