flow table format specifier rules (14.0)

Hello,

I seem to be able to create a flow table in which an entry is identified
only by the
protocol type and destination port but adding to it returns an error.
Must a flow specifier always contain src-ip or should I be able to define a
flow
like "incoming UDP traffic from any to port 53" and also use it?

#created OK
ipfw table t4 create type flow:proto,dst-port

ipfw table t4 detail

--- table(t4), set(0) ---
 kindex: 10, type: flow:proto,dst-port
 references: 0, valtype: legacy
 algorithm: flow:hash
 items: 0, size: 296
 algorithm hash info
  size: 512 items: 0 itemsize4: 32 itemsize6: 56

#can't add a
ipfw table t4 add 6,2 0

ignored: 6,2 0
ipfw: Adding record failed: Invalid argument

# this will work
ipfw table t6 create type flow:src-ip,proto,dst-port

ipfw table t6 add 2.2.2.2,6,2 0
added: 2.2.2.2,6,2 0


Thank you,
Adrian