FOR followers of the arcane details of the independence debate there was quite a lot that sounded rather familiar in yesterday's much-heralded launch of the Scottish Government's proposals for an independence referendum.

Although this may have been the first time that much of the outside world has taken an interest in Mr Salmond's plans, this was the fourth major document on the subject the First Minister has launched since he first came to office in 2007. Inevitably, there was a fair amount of repetition.

Yet there was also some important shifting of ground. Above all, although Mr Salmond still insists that Holyrood does have the ability to hold an independence referendum so long as it is carefully worded to conform to the limitations of the Scotland Act, he is now no longer seeking to do so.

Instead of the convoluted wording any such referendum necessarily entails, the SNP now wishes to hold a simple Yes/No vote on a straightforward question on independence.

That, as Mr Salmond acknowledged yesterday, undoubtedly requires Westminster to transfer the necessary powers.

That means he eventually is going to have to try to secure agreement with the UK Government on how the referendum is conducted.

Some of the more detailed changes of mind that were unveiled yesterday look as though they could help smooth the path towards an eventual resolution of the dispute between the two governments.

First of all, Mr Salmond has shifted his position closer to that of the UK Government on how the referendum should be run.

Two years ago, he anticipated giving responsibility for regulating and monitoring the referendum to a specially created Scottish Referendum Commission.

Now he is willing to accept the UK Government's argument that the UK Electoral Commission should perform those roles, so long as it reports to Holyrood rather than Westminster.

Mind you, unlike other recent referendums, the Electoral Commission is not to be given overall responsibility for actually running the referendum.

Nevertheless, the issue now no longer looks like the potential flash- point between the two governments that it appeared a week ago.

More intriguing in that respect is a second change from previous SNP documents.

The latest document says much less about the mechanics and details of a possible second question on devo-max.

Two years ago, we were given details of how that question might be asked and how it would be decided which option had won.

This time such details are entirely absent, instead the paper simply seeks views on the principle of whether that option should appear on the ballot paper at all and says it would take advice on how it would be decided who had won.

In so doing, Mr Salmond is deftly keeping his options open. For the time being he wants to keep his "consolation prize" alive, should the poll numbers on support for independence continue stubbornly to fail to move.

But perhaps he is also making it easier to drop the second question, should his consultation fail after all to show a strong demand for the inclusion of this second option on the ballot paper – and should its potential inclusion eventually stand between him and reaching an accommodation with the UK Government.

The two governments do still remain at odds with each other on two other issues, where, for the time being, Mr Salmond is sticking to his guns.

The first is on the timing of the referendum. Here the UK Government will probably have little option but to give way, comforting itself with the thought that at least the vote will be taking place in 2014 rather than 2016.

The second is whether 16 and 17-year-olds should be allowed to vote. On this, the truth is that the ability of the SNP to implement its idea is heavily constrained by existing electoral registration law and practice, over which it has no control.

In practice these constraints mean that, at most, only some 17-year-olds would be able to vote in any referendum held in the autumn, as only those whose 18th birthday falls before December 1 will be on the register anyway.

In these circumstances it seems difficult to believe this is an issue the SNP would allow to scupper an agreement .

Two weeks ago, we were in the midst of a blazing row between Edinburgh and London.

The tension is still there, but Mr Salmond may now have helped pave a path towards eventual harmony after all.

l John Curtice is professor of Politics at Strathclyde University