target = "https://www.rfc-editor.org/rfc/rfc9000#section-9.7"

# 9.7.  Use of IPv6 Flow Label and Migration
#
# Endpoints that send data using IPv6 SHOULD apply an IPv6 flow label
# in compliance with [RFC6437], unless the local API does not allow
# setting IPv6 flow labels.
# 
# The flow label generation MUST be designed to minimize the chances of
# linkability with a previously used flow label, as a stable flow label
# would enable correlating activity on multiple paths; see Section 9.5.
# 
# [RFC6437] suggests deriving values using a pseudorandom function to
# generate flow labels.  Including the Destination Connection ID field
# in addition to source and destination addresses when generating flow
# labels ensures that changes are synchronized with changes in other
# observable identifiers.  A cryptographic hash function that combines
# these inputs with a local secret is one way this might be
# implemented.

[[spec]]
level = "SHOULD"
quote = '''
Endpoints that send data using IPv6 SHOULD apply an IPv6 flow label
in compliance with [RFC6437], unless the local API does not allow
setting IPv6 flow labels.
'''

[[spec]]
level = "MUST"
quote = '''
The flow label generation MUST be designed to minimize the chances of
linkability with a previously used flow label, as a stable flow label
would enable correlating activity on multiple paths; see Section 9.5.
'''