[ns] Difference between "-Pms" and "-Ps" in wireless trace files

[Salvo Danilo Giuffrida]

Hello, I'm trying to analyze a trace file which represents traffic
inside a wireless ad-hoc network, and uses the new trace format. I've
not yet been able to understand the difference between the elements
"-Pms"
"-Ps"
"-Pmd"
"-Pd"

They appear when an ARP Request/Reply is sent/received, but the NS2
manual doesn't explain completely the difference between "-Pms" and
"-Ps", and between "-Pmd" and "-Pd". In fact, there' s written
-Pm: src mac address
-Ps: src address
-Pa: dst mac address
-Pd: dst address

Which, by the way, is partially wrong (there's no "-Pa", I guess that
stands for "-Pmd", and there's no "-Pm" either, which I guess stands
too for "-Pms")....I don't understand anyway what's the difference
between "src mac address" and "src address"...
Thanks a lot