There's an article on the BBC website that attempts to explain the system of autonomy in Catalonia - ie. the one that Madrid is today trying to sweep away and replace with a puppet regime. Unfortunately, however, the article makes a comparison with devolution in Scotland that is astonishingly misconceived in the light of recent events...
"The division of powers between the central government in Madrid and the regional government in Barcelona is not as clear cut as it is in some other countries with devolved authorities such as Germany or the UK. In the UK, for example, the government in Westminster cannot interfere in Scottish education policy because education is fully devolved."
Oh really? Agriculture and fisheries are "fully devolved" in Scotland, and yet the UK government are doing a remarkably convincing impersonation of a group of people who think and know that they have the legal right to interfere with Scottish agriculture and fisheries to their heart's content under the cover of a post-Brexit power grab. The reason? First of all, the Scotland Act stresses that none of its provisions prevent the UK parliament from "legislating for Scotland". The only constraint on Westminster legislating on devolved matters is the informal Sewel Convention, which was supposed to have been put on a statutory basis as part of the implementation of "The Vow". However, earlier this year the UK government successfully argued at the Supreme Court that the whole thing was a con-trick and that Sewel remains legally unenforceable.
Secondly, the Scotland Act specifies that 'the constitution' is reserved to Westminster - an extremely broad category that naturally includes the Scotland Act itself. So Westminster can simply rip up or modify the devolved settlement at its whim - which is exactly what it is currently attempting to do by means of the Great Repeal Bill. The only conceivable constraint on that process is Sewel, which is legally worthless (see above).
As I've conceded before, the UK does have a good story to tell in the sense that it's extremely unlikely that a violent Spanish-style crackdown would ever be launched against an exercise in Scottish self-determination. But the idea that Scotland has some sort of clear-cut legal protection that Catalonia lacks is an absolute fairy-tale.