The legal minima is the System Minima. For practical purposes in light aircraft even IR rated pilots do not use this because their altimeters are uncalibrated, they add PEC.
The AIP advises IMC rated pilots to add the prescribed heights to give the minima you are all quoting. The Law however does not prescribe these additions, so unless you come below the system minima you are not illegal. To find out what is legal just read the ANO.
Common sense dictates that pilots scale their minima to match their experience. Hopefully we don't need laws to enforce common sense.