and it is higher than 1/4th for all seasons listed on that website and I think it is in every league. Can you give some credible link about the 1:4 saying?
I don't know how La liga comes up with the numbers but they look at a couple of things including the debt of that team. This is why it was difficult for Barca to register players.
This is the 1:4 rule by which clubs are allowed to invest €1 for every €4 they saved. Put crudely, offload a player for €10m and you can invest €2.5m. Or if that player alone accounts for 5% of their budget, they can invest 50% of what is saved.
If you read
this article you'll see how a big news media house like ESPN say in 2020 that Barcelona won't be able to sign or register players like Lewandoski, Raphina and Kounde, but these 3 are Barcelona players today. And this is the kind of news that people believe. Barcelona have problems, but the problems are exaggerated by the media.
Yes, they obviously exaggerate in many regards as the doomsday which they always predict never comes true. But regarding financial fair play rules and penalties for violating them, I still think this will never come true in a serious way that would literally eliminate a club like Barcelona from La Liga and send them to Segunda division. Think about the damage that would cause to the league domestically, but also for the UEFA in terms of representation of the best football in the world. It's like Formula 1 excluding Ferrari and Mclaren or RedBull for a year. They would always agree on some penalty that still allows them to drive in the highest division.