G clef (usually treble), F clef (usually bass) and very movable C clef (alto/tenor) are all very definable, as are the dots contained within.
Look at untuned percussion music, though, and there's only slight, if any standardisation. Often there's not even a legend at the top telling what each dot represents. Reading a lot of it requires intuition and some guesswork.
Understanding that there are many different untuned percussion instruments that would all require a special place and/or symbol, but also understanding that most 'standard' drumkits are basically five shell and hi-hat plus two cymbals (others are personal choice, but are options for the particular player, so don't count), why is it no standardisation is available? Or is there and I've missed it? Or is it like betamax and vhs, and we're still waiting for a winner?