Recently, Howland wrote this in an announcement about PvP with kobolds/goblins:

The main PvP guidelines still apply, however. If the PvP occurs in an area with NPCs, a DM must be present. Regardless of NPC presence, a DM tell should be sent alerting us to the PvP so if anyone is online we can watch. Likewise, if you RP a character that hunts down goblins/kobolds it is of course fair for these PCs to respond in kind.

The streets of Lower are increasingly chaotic, and although we prefer every effort be made to find a DM before PvP occurs in this area if that is impossible it is generally acceptable to engage in PvP in the streets themselves. Areas such as goblin town, inns, taverns, populated faction areas, etc. -must- have a DM present for any PvP.

In the 1st paragraph, it states that a DM must be present in any area that contains NPC's. Yet in the 2nd paragraph, it states that it's generally acceptable to engage in PvP in the streets themselves without a DM presence. Could a DM clarify this in relation to, say, PvP in front of the merchants (Speckard, Mikkelson, et al) or in front of quest-givers (Mary, Wally)? Do "streets" mean ANYWHERE outside? Or does it mean anywhere outside that there aren't major NPC's present?

Also, when I advised a player today to make sure he sent a tell to the DM channel that he was actively pursuing PvP, the player sent me a tell back saying that a DM on-line told him such notification wasn't necessary. My understanding (as Howland stated in the above quote) is that you send a tell to the DM channel when you are about to engage in PvP, regardless of NPC presence?

You send a tell always.

In Lower (even in front of Lower NPCs), you can pursue PvP - but you still should make an effort to get a DM. It's mostly for situations where there's no Dms online. But you should still always send a tell.