A stained rag can mean any number of things, it can be used to neaten the edges of something wiping it so the lines are clean or something used to mop spilled liquid. A stained shirt or item of clothing is more serious, it becomes unusable because it is unclean, stains are often hard to remove some are even permanent, you soak your favourite top in some god awful chemicals to try and remove the oil stain from the previous night, you would have normally bothered but it was your favourite top and there was no replacing it but stained it was worthless there was no wearing it and on that basis there was no point in keeping it full stop. It’s a shame that some things have to be thrown away but nothing goes on forever and they make way for the new coming through.
We often used to associate stained with older or antique items such as letters, manuscripts and books but with the digital age now fully upon us there is no age tinted books of records they are all clearly displayed in black and white on a screen the author can be traced to the computer within reason so there is no doubt of who made the records and how the information was entered into the database. A stained computer would be worthless if the liquid had seeped into the electrics and blown all the circuits up, we found stains on paper to be endearing but blind panic ensues when there is moisture near the computer.
As the world progresses there are plenty of things which get replaced with new parts because the old ones are now obsolete, perceived to be worthless because they have been superseded, they are exchanged for new models which promise a even bigger world than the previously discarded item. Its the same for stained items, they are replaced by things that aren’t marked forever so they are newer and better by definition. Then time steps in and works its magic, then we are back to stained or deprecated parts which need replacing.