target = "https://www.rfc-editor.org/rfc/rfc9000#section-12.5"

# 12.5.  Frames and Number Spaces
#
# Some frames are prohibited in different packet number spaces.  The
# rules here generalize those of TLS, in that frames associated with
# establishing the connection can usually appear in packets in any
# packet number space, whereas those associated with transferring data
# can only appear in the application data packet number space:
# 
# *  PADDING, PING, and CRYPTO frames MAY appear in any packet number
#    space.
# 
# *  CONNECTION_CLOSE frames signaling errors at the QUIC layer (type
#    0x1c) MAY appear in any packet number space.  CONNECTION_CLOSE
#    frames signaling application errors (type 0x1d) MUST only appear
#    in the application data packet number space.
# 
# *  ACK frames MAY appear in any packet number space but can only
#    acknowledge packets that appeared in that packet number space.
#    However, as noted below, 0-RTT packets cannot contain ACK frames.
# 
# *  All other frame types MUST only be sent in the application data
#    packet number space.
# 
# Note that it is not possible to send the following frames in 0-RTT
# packets for various reasons: ACK, CRYPTO, HANDSHAKE_DONE, NEW_TOKEN,
# PATH_RESPONSE, and RETIRE_CONNECTION_ID.  A server MAY treat receipt
# of these frames in 0-RTT packets as a connection error of type
# PROTOCOL_VIOLATION.

[[spec]]
level = "MAY"
quote = '''
*  PADDING, PING, and CRYPTO frames MAY appear in any packet number
space.
'''

[[spec]]
level = "MAY"
quote = '''
*  CONNECTION_CLOSE frames signaling errors at the QUIC layer (type
0x1c) MAY appear in any packet number space.
'''

[[spec]]
level = "MUST"
quote = '''
CONNECTION_CLOSE
frames signaling application errors (type 0x1d) MUST only appear
in the application data packet number space.
'''

[[spec]]
level = "MAY"
quote = '''
*  ACK frames MAY appear in any packet number space but can only
acknowledge packets that appeared in that packet number space.
'''

[[spec]]
level = "MUST"
quote = '''
*  All other frame types MUST only be sent in the application data
packet number space.
'''

[[spec]]
level = "MAY"
quote = '''
A server MAY treat receipt
of these frames in 0-RTT packets as a connection error of type
PROTOCOL_VIOLATION.
'''