Not a great deal, one might imagine.
But the precedent set by a European Economic Community-appointed panel consisting of Roman Herzog (president of the Federal Constitutional Court of Germany), Aldo Corasaniti (president of the Constitutional Court of Italy), Franciso Tomás y Valiente (president of the Constitutional Tribunal of Spain) and Irene Petry (president of the Constitutional Court of Belgium) and chaired by Robert Badinter (president of the Constitutional Council of France) at the end of a process lasting between 1991 and 1993 may have some impact on the decision Scots make in nine months time.
In late 1991 the former British foreign minister Peter Carrington asked several questions pertaining to the then-ongoing situation in the Socialist Federal Republic of Yugoslavia, a multi-national European state which was in the process of undergoing secession of several of its member states.
The most pertinent question asked by Carrington was that if one or more constituent nations seceded from SFR Yugoslavia, did SFR Yugoslavia continue to exist - as claimed by the entities (the Socialist Republic of Serbia, the Socialist Republic of Montenegro, the Socialist Autonomous Province of Vojvodina and the Socialist Autonomous Province of Kosovo and Metohija) which had remained - or alternatively did the international community regard SFR Yugoslavia as dissolved with each republic being an equal successor to the state.
The Commission ruled that
the Socialist Federative Republic of Yugoslavia is in the process of dissolution
The Commission further ruled, at the same time, that the international community in general and the EEC (now the European Union) in particular should recognise the independence of the so-called "Republic of Macedonia", the Republic of Slovenia, but not the independence declarations of the Republic of Croatia (citing concerns over a lack of protection for minorities incorporated into the constitution, a deficit was which immediately remedied by president Tuđman and followed equally swiftly by the recognition of Croatian independence) or the Republic of Bosnia-Herzegovina on the grounds that unlike the other seceding Republics, Bosnia-Herzegovina had never held an independence referendum. Ultimately, the horror which subsequently unfolded in Bosnia and Herzegovina - provoked in large part by Arkan, a war criminal who was sponsored by BetterTogether's main funder Ian Taylor - led to a permanent withholding of independence of the Republic, until a merger with the (Croatian) Republic of Herzeg-Bosnia to form the Federation of Bosnia and Herzegovina, which subsequently and indisolubly merged with the Republika Srpska to form the modern state of Bosnia-Herzegovina.
So far, so straightforward. The precedent set by the European Union is clear and unambiguous, and supported by the Constitutional Courts of the most important European states: a nation which wishes to secede from a multi-national state is entitled to international recognition provided secession has received the consent of the population, regardless of the wishes of the population of the rest of the state outwith the seceding nation.
Furthermore, subsequent opinions by the Commission considered the problem of State Succession resulting from secession.
In Scotland, we are constantly and loudly told by the Tory-led Unionist campaign that Scotland's declaration of independence in 2013 (which will be confirmed in a referendum in September this year) means that we will be leaving the United Kingdom, which will carry on as the successor state. They even have a name for it: rUK (I prefer fUK, for "former UK", but appreciate that there are reasons why this may not gain traction in the popular press).
This - we are told - presents several problems for Scots. We would be thrown out of the European Union (despite the fact independence will be confirmed in September, leaving eighteen months to negotiate continued membership of the EU for one of its richest, most strategically-vital territories. Scotland will not be an independent state until March 2016, and only then could the EU begin moves to expel Scotland. At this point, it is worth noting that when Greenland resigned from the EU in 1979, it took more than six years for its membership to cease. One can only begin to imagine how much longer it would take the EU to expel a state which desires to continue its membership - even if it had the inclination to do so) because we "would not be the successor state".
Given that the Commission (in Opinion 9) considered that the membership of the SFR Yugoslavia in international organisations could not be continued by any of the successor states (FR Yugoslavia (consisting of Kosovo and Metohija, Montenegro, Serbia and Vojvodina), Bosnia-Herzegovina, Croatia, Fyrom and Slovenia), but with an equitable division of the international assets and obligations of the former SFR Yugoslavia, and new applications for membership by each successor republic to organisations such as the United Nations, FIFA and so on, is it completely inconceivable that, faced with a xenophobic, anti-European government of spivs and bigots in Whitehall, who wish to either withdraw from the EU in its entirety or ignore its raison d'etre of free movement of capital and labour, the EU might choose to regard Scotland as the successor state rather than the former United Kingdom, particularly with a referendum on British secession from the EU on the agenda which is extremely likely to pass (certainly on the basis that pro-EU Scotland will have withdrawn from the UK and be unlikely to have a vote)?
This would simultaneously solve the problem of reluctant British membership of the European Union (they get to leave), and allow Scotland to remain part of it. It would solve a serious problem for Madrid (the government would not be seen to give assent to Scottish membership, allowing it to present its own Catalan problem as the entirely different scenario of a territory of a unitary state, not a nation in a multi-national state, unilaterally seceding).
If FR Yugoslavia is legally not considered a continuation of SFR Yugoslavia, it is hard to see how fUK could be considered as the legal continuation of the United Kingdom by the same organisation.
A further precedent which ought to give cheer to pro-democracy campaigners is that of Saint Martin and Saint-Barthélemy in 2007. These two French colonies seceded from Guadeloupe, itself a French colony, and (significantly) an Outermost Region (OMR) of the European Union. An OMR is part of a European Union member state situated outside the European continent but which is comprehensively part of the EU.
Saint Martin and Saint-Barthélemy were part of the European Union exclusively as a product of their being a part of Guadeloupe (much in the same was that we in Scotland are told today that we are only part of the EU because of our membership of the UK). When they seceded from Guadeloupe, they became OMRs of the EU in their own right.
If Scotland wishes to remain part of the European Union after independence, there is no legal or constitutional barrier in its place.