1) By authorised they mean they have put you on their hit list. It's nothing official.
2) Probably. The problem with analogue sets is that they often show an image even when the aerial is disconnected. Any hint of an image and they would deem the equipment to be installed. If the equipment is installed and the property doesn't have a valid licence, then you'd have a problem.
3) The warrant permits them to search for TV equipment only. They can't rifle through your wife's underwear drawer (much as they'd like to).
4) No. It is their policy not to do that.

  to this forum MrDizzla. To answer your questions:
 
1). No it doesn't. It means that somebody has told somebody else to pop round, say hello and attempt to sell you something. And that's all it means. The phrase authorised to visit your address is one beloved of marketing companies (such as Capita Business Services, lead company of the group operating under the BBC's direction and using their tradename, "TVL"), attempting to drum up business using legal-sounding and threatening language.

2). They could, as CountryBoy says. However if you film them fiddling and twiddling with your tv then it's on record that it's them (and not you) who is attempting to tune in the tv. It's also proof that broadcasts were not being watched at the time. You're perfectly within your right to film something like this in your own home - and they won't like it one little bit.

3). There'll be no "Raid". If you're referring to a search warrant they can only search for what is specifically mentioned/listed in the warrant and only in the areas designated for searching stated in the warrant. Only TVL staff should be doing any searching in this case as the warrant has been applied for by and granted to them and not the police. The police are not involved in the actual search; it isn't the reason the police are called: they are there only to prevent a breach of the peace and should not be helping out in any way in the physical looking.

4). No. TVL's own policy states that they won't do this. I don't know of any instance on record where this has been done.
 
One document is below. I have another one somewhere and when I find the ruddy thing I'll post it here.
 
Found it. It's the same one that CountryBoy posted in another thread You are not allowed to view links. Register or Login.
In that 89-page document (IR2008037) it's stated very clearly in section 2.9 on page 80.
 
 
 

There's no guarantee that they won't. However this is against Capita Business Services' written policy and I'm more than certain that the N.I. police service have far better things to be doing with their time and resources than this.
 
[Capita Business Services are the lead company of the group of companies who do the business of collecting money for the BBC under the BBC's tradename of Television Licensing; or if you prefer, The BBC's outsourced revenue extortion service].
 
If you have the misfortune of encountering the more thuggish-type of bully it's not beyond the bounds of possibility but even then if you stand up to them I think it's pretty unlikely that that's ever going to happen.
 
Remember the power of the camera, the camcorder and the taperecorder. Always useful and especially so in a situation like this if indeed it should ever arise.

This thread demonstrates how wrong certain people, in "another place", are, when they state that the letters aren't confusing/misleading, and that nobody can/will be fooled into acquiescing to TVL's demand/request, to search their home, take a "statement under the relevant law", etc.

Those certain people you refer to refuse to see the truth, I have been reading a couple of threads over there, it just keeps going round and round in circles.  It seems the prerequisite for being pro BBC is to be pedantic over the smallest detail or choice of wording.

I just looked at registering at DS - £5 to register on their forum!!!!!
  that

I just looked at registering at DS - £5 to register on their forum!!!!!
  that

To be fair that is only for an " anonymous email address (such as those provided by Hotmail, Google or Yahoo) " it's a good way to stop spam . 
Spamers are quite a problem on the net ,I had to remove a  ad web link from a new member's (spamer's) profile just today.
It appears they post links on any forums they can find & make money from any click throughs   they get .