section 4 clarify scan phase

[Xavier Vilajosana]

18. The third paragraph of section 4 is completely unclear to me:

A Node aiming to join the network by receving a properly formed BEACON shall enter in a scan phase and shall store the value of macPANId and then set it to 0xffff for the duration of the scan in order to meet the filtering rules in [IEEE802154].

What are "macPANId" and "scan phase"? I don't see those terms used anywhere else in this document; do the terms come from the IEEE 802.15.4 specs? Why would an implementation store the value of macPANId and then set it to 0xffff?

TW> Edtorial. TW> @Editor, please fix.