Which, by elimination, means that the Mercer House isn't a Covenant.
True
If a Covenant sets up without seeking Tribunal permission ,
then the local Tribunal need not enforce The Code in relation to these Magi.
This is the province of whichever Tribunal you are registered with.
A rival (and recognized) local covenant simply claims the area that your unregistered covenant has set up.
The local Tribunal agrees that your unregistered Covenant is depriving these fine upstanding Magi of their magical power.
They direct you to vacate immediately (via Redcap) and to report to the local Tribunal without delay.
If you refuse to follow a direct request of the local Tribunal , you are guilty of a High Crime and have forfeit immunity.
I still disagree with you Ravenscroft, although a little less then before. It is important to distinguish between formal and applied law and you mix them up. Especially in the former post. A covenant not reckognised by the regional Tribunal might easily become victim of biased rulings in their disfavour, simply because they do not have a pull at the meetings, but there's still the basic rights of the Oath which apply in their favour nonetheless and protect them formally regardless of reckognition.
Yes and no. The Tribunal might choose never to raise a case involving the covenant in question, but in formal terms the magi of said covenant do not enjoy less protection from the Oath. Breaking the Oath against them is no less a crime than against mage of other reckognised covenants. Choosing not to enforce the Code is a case of applied law, and not a formal legality, and doing so would not only require a majority of votes, it would also require the Praeco and espescially the presiding quaesitor to back it, and for the quaesitor this surely puts his reputation as such and with the House at stake.
Ownership of ressources are registered with the Redcaps and it does not depend on Tribunal reckognition. This system is there to ensure that in such a case a magus (or covenant) can be testified to own a ressource even if not reckognised. A tribunal might make biased decisions - but then it is not a case of formal rights, but an abuse of the application of said rights.
True. Refusing to follow a Tribunal decision especially on you is a High Crime and is thus under pains of losing your life. That is true however biased or illegal that decision is. But the point is that the covenant is now a legitimate target because of a specific process at the tribunal concerning them, not as a defualt of not being reckognised.
Defending yourself from attack does not forfeit your immunity, no matter the legality of the attack, and on the other attacking someone you forfeit your immunity towards them. Forfeit immunity is all about who can legally attack who and nothing about who can defend themselves from attacks on themselves.
Finally forfeit immunity is only a term used in media res or at Tribunal in retrospect, for example when judging whether some action against some other magus was justified, when it comes to judging crimes and setting punishment the transgressor ultimaly is cast out and Marched - thus actually loosing their status as members of the Order and thereby loosing their immunity for good. You only forfeit your immunity temporary, and even then the response and use of force against you should be proportionate, but you loose it permanently if Marched.
Using the claim that "I registered my Vis Sources with the Redcaps first"
does not give a Covenant legitimacy under the Code , afaics.
The local Tribunal is still deprived of those resources ,
regardless of whether they previously knew of their existence.
Curious it is then that HoH:TL say of registering your vis with the Redcap thusly (p. 83): "This allows covenants to legally protect their resources without necessarily making them public".... 
It may well say that , but you are still in another Tribunal and the original ownership of those resources is under dispute.
You may have found them and claimed them and say
"I legally found them and registered them , so they are mine , you bastards." 
but if the local Tribunal disputes your residency ,
and claims that all resources in their purview are legally theirs ,
or legally belong to any sanctioned covenant to claim as and when they choose to do so ,
you have committed a crime by stealing/"claiming" them first.
Just because they did not know about any Vis sources and chose not to exploit them , does not mean that they can't claim them after the fact.
It is certainly not a crime or stealing in itself to claim a vis source unclaimed by others, and no one could attack them on sight claiming they forfeit their immunity by doing so. That would simply be against the Code and no regional Tribunal can rule against the Code.
If however the regional Tribunal makes a ruling on this matter against said covenant, and they refused to follow such a ruling, only then would they become a legitimate target. But then we are back at applied hermetic law, gathering consesus vs the covenant, rather than formal law.
From page 45 , True Lineages
Again , my point is , that the unsanctioned Covenant in the local Tribunal deprived a sanctioned Covenant of those Vis sources.
Just because you found them and claimed them first ,
does not mean you have not committed a High Crime by so doing.
That is a complete distortion of the Code; That using unclaimed vis is a High Crime; That you could deprive someone of something that they have not know about, much less claimed or have had registered at the Mercere.
A silver tongue and strategist might make such a case and win it at Tribunal, but it is contrary to the Code, and thus in the realm of applied law, and not formally within hermetic law.
Which returns to my point, that there is amble opportunity for discriminating an unreckognised covenant, you might even within the regional Peripheral Code make it possible to make terms so untolerabel to the unreckognised that they will in the end either leave or transgress enough to make them legitimate targets. But you cannot make it legal to attack them outright or, as you argued earlier, disallow them to defend themselves from such an attack.
I never claimed that using unclaimed Vis was a High Crime.
My assertion was that by your unsanctioned Covenant moving in and claiming it ,
you are depriving a sanctioned Covenant of its magical resources.
That it does not matter under the Code that it was undiscovered previously.
Afaik , there is no provision in the code for Terra Nullius.
Another link for Terra Nullius
Does the Code make provision for any Hermetic Magus to move into any area ,
and so long as no-one has previously claimed (via the Redcaps) any magical resources in the area ,
they are free for the taking?
(Btw , i hope you don't think i am arguing because i think you are wrong or anything)
Actually you did.
It is the same thing. Disputes of vis sources are handled at tribunal. That alone might very well hamstring the unreckognised covenant, but the register of the Mercere is used as legitimate claim - if you haven't registered it with the Mercere your case will be quite difficult and most will loose it. But in any instance this is not proportionate to allowing or justifying random attacks.
Using an unused vis source in a tribunal is not depriving anyone of their power.
No there is no notion of Terra Nullius in the Code. Nor am I claiming that. Moreso since it is an inappropriate term in the context, used in another time to justify other acts.
Yes - or rather the Code makes no provision against it. A regional Tribunal might in its Peripheral Code make provisions against it or make it more difficult. But there would still be stretch from there to making it a High Crime of the sort justifying attacking without due proces.
I don't really see the concept of Terra Nullius as totally inappropriate in this context.
The local Tribunal has for whatever reason not fully exploited the area it claims jurisdiction over.
Therefore any Magus or group thereof can move in to any Tribunal and "stake a claim" ,
fully protected by The Code in their right to do so.
Without anything added in the Peripheral Code individuals and covenants claim vis sources, tribunals do not.
My confusion about Tribunals , is that i am seeing them as a collection of Covenants ,
not as a body like the UN.
That the voting residents who claim membership or residency in a local Tribunal ,
do not have a vested interest in protecting their investment seems odd.
On the Founding of Covenants page 16 , Rhine Tribunal (GotF)
This is in relation to the First Tribunal.
While the specifics of how a Covenant obtains recognition may differ from tribunal to tribunal ,
we have nothing in current canon to say if all other Tribunals either follow or ignore this procedure.
I was reading through the history of the order and came across the following
942 1081 Stonehenge: Contact lost with London covenant, which had moved in the city repeatedly. [HtM]
952 1091 Stonehenge: Nova Roma magi report contact with magi of London covenant, in a clash over a vis site. No further contact with London covenant reported. [HtM] London covenant had always been mysterious. Its fate remains a secret, but they left no one behind to care.
So their is precident in "secret" vis sites. Granted this is between 2 covanents but the same should apply for lone Magi
It has already been noted earlier in this thread that some Tribunals, including the Rhine, in their Peripheral Code have set forth standards of reckognition.
Concerning this reference one thing is of importance, namely the use of the term "the First Tribunal". In terms of the Hermetic Law (especially found in the HoH:TL) the term First Tribunal is often used as a reference to the Tribunal held prior to division of regional Tribunals and the Grand Tribunal. The rulings of this proto-Grand Tribunal are binding to all magi and tribunals and can only be changed (if at all, as some traditionalist Quaesitors would question) by a Grand Tribunal. The term "First Tribunal" is however also used, yet in another capacity, by the magi of the Rhine Tribunal when speaking, with pride, of their own regional tribunal. This however does not make the rulings of the Rhine Tribunal binding to anyone else - although the regional tribunals often take heed of other tribunals way of solving issues. The reference you present use term in its second capacity and the reference even starts by stating it to be a decision of the Rhine Tribunal, which out of good faith you ought to have included in your argument. Especially since it is the key to realising that said ruling is not binding to any other regional tribunal, and thus the question of needing reckognition is still a regional issue.
I definately do not see them as the UN either, although the difficulties toward multilateral action is somewhat similar. I have attended the UN General Assembly in NYC, and although my experiences there could probably inspire several stories of political intrigue and relations, it is not how I imagine a Tribunal of magi unfold. 
I do not claim that they don't, only that the means of protection vary in terms of formal hermetic law according to the local (regional) Peripheral Code, or by using various non-legal (not necessarily unlegal) means to discourage new covenants.
And although some resident magi might not wish to share the existing resources in a Tribunal, there might be many other reasons for other resident magi not to be contrary to having more covenants or magi in the tribunal. To offset the current balance in the Tribunal, to have a stronger Tribunal (both in sense of votes at the GT aswell as for the pride), to have more likeminded magi of a shared House, Cult, stance or interest, to be stronger toward non-hermetic threats, or out of genuine benevolence toward ones sodales. These examples are just to highlight that the motives involved are much more varied than protectionism alone.
Yes - and the HoH:TL section on the Mercere tell that the Redcaps keep a confidental register of vis sources for exactly that reason, so as to be used in any future settlement of conflicts over vis, and that your sources can be registered there whether you or your covenant is known to the Tribunal. This register is open to covenants aswell as individual magi.
On a sidenote, the Stonehenge has been troubled with an unsteady Tribunal tradition, with long periods without quorate tribunals and with a few covenants only popping up once awhile. Even though some might prosper from the chaos others might be interested in more covenants alone for the reason of making the tribunal more stable and the tribunals effective.
Well , refering to the Rhine Tribunal i did not mean they were The (Capital T) First Tribunal ,
merely the First Tribunal. 
The ruling on unrecognized Covenants has been around for more than a few years within the Rhine Tribunal.
It would be of great surprise to me if the Tribunals founded by members from the Rhine Tribunal
did not copy them to some degree in this regard.
The Recognition Factors may change ,
but being able to persecute unsanctioned covenants and "take their stuff" without reprisals ,
seems like too good a deal to pass up.
(as long as their individual rights are respected of course)
You did?
Then I must have misread the following:
The only thing I see you question is what procedure of reckognition is followed, not the reckognition in itself. There is no follow or ignoring issue if said procedure was never decided upon by the Grand Tribunal or your own regional Tribunal.
No unreasonable. But you keep argueing in terms of formal law. It is only formal if decided upon by the regional Tribunal. Some Tribunal supplements specify such rulings, other do not, and yet others havent been published yet. Thus in most cases this is a question of how you carve out the tribunal of your saga.
I will not repeat the arguments from above, just say that said deal might not be the motivation of every magi attending the tribunals deliberating such a ruling. Secondly, there is a formal limit to persecuting and taking without reprisals and respecting their individual rights.