Dishwasher safe is a real rating and it describes survival rather than no change at all.
What the Rating Means
That the piece withstands normal household dishwasher cycles without the glaze failing or decoration coming away.
It is tested over a defined number of cycles. It does not promise that a matte finish will look identical after a decade of daily washing.
For fully vitrified stoneware and porcelain with under-glaze decoration, the rating is generally robust.
What Actually Causes Damage
- Pieces knocking together during the cycle, which chips rims
- Overloading, which is why that happens
- Detergent that is too aggressive for the water hardness
- Very hot cycles used routinely rather than occasionally
- Metal items resting against ceramics
- Unglazed foot rings scraping other pieces
Guidance that a range is rated for household dishwashers, of the kind given at https://famiware.net/, is about the glaze surviving; how you load the machine decides whether the rims do.
Loading Matters More Than the Cycle
The practical point. Most dishwasher damage to dinnerware is mechanical rather than chemical.
Plates spaced so they do not touch. Mugs secured so they cannot invert and fill. Nothing wedged. Bowls angled so they drain rather than holding water.
A packed machine is also a machine that does not clean properly.
Detergent and Hard Water
Too much detergent in soft water leaves residue and can etch some glazes over time. Too little in hard water leaves mineral film.
Matching the dose to your water hardness, which suppliers publish by area, is worth doing once.
A cloudy film that wipes off is limescale. One that does not is etching, which is permanent.
Metallic Decoration
Gold and platinum banding is the exception to most dishwasher claims, and it wears with repeated cycles.
Hand washing anything with metallic decoration is the safe default.
Unglazed Feet
The rough ring on the base is unglazed on most ceramics, and it is abrasive.
Stacking glazed face to glazed face rather than base to face prevents ring marks.
Let It Cool
Unloading immediately after a hot cycle onto a cold worktop is a temperature change.
Do Not Overload
Which covers most of this.