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Now I believe in most European countries it is common to use unfused plugs and a 15A radial circuit so all your cables must be capable of carrying 15A up to the point of the internal fuse in a device.
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That's correct, at least for what I can tell for Germany.
Usually in domestic installation (industrial or power distribution will be significally different), you will have a distribution system, which is not accessible to the common user.
Only the final distribution board, located e.g. in the apartment, would be accessible to the user.
Also, we do not use fuses, but Miniature Circuit Breakers, which can be safely operated without accessing the actual circuitry or exposing live parts.
Most commonly, the distribution board will be supplied via a 32A MCB, located in the house's MDB. (Old MDBs might still have screw-in fuses of D02 type)
Behind that, you will have 16 A MCBs for sockets and lighting, and maybe some 20A or 25A 3-phase MCB for stoves and heating.
Thus, all the installation has to be rated for 16A up to the socket (which has to be of Schuko type).
From there you can deviate. Schuko will always be 16A rated, the smaller Euro plug is 5A rated, if I remember correctly.
Mobile appliances might have additional fuses inside, if this is necessary due to their rating. A common use here is a glass fuse rated 250V with smaller amps rating like 200mA, 500mA, 1A etc.
btw: As far as I know, the British Standard ring structure is illegal in Germany. (Correct me, if I'm wrong)