ISO 5775 is an international standard for labeling the size of bicycle tires and rims. The system used was originally developed by the European Tyre and Rim Technical Organisation (ETRTO). It is designed to make tire sizing consistent and clear. It replaces overlapping informal systems that ambiguously distinguished between sizes. For example, at least 6 different "26 inch" sizes exist (just by American notation), and "27 inch" wheels have a larger diameter than American "28 inch" (French "700C") wheels.
Wired-edge tires can be mounted on straight-side or crochet-type (aka hook bead) rims. Such tires are designated with their nominal width and their nominal rim diameter, separated by a hyphen (-). Both are measured in millimeters. A typical example of a tire marking according to ISO 5775-1 is:
Off with your head
Dance 'til you're dead
Heads will roll, heads will roll
Heads will roll on the floor
Glitter on the wet streets
Silver over everything
The river's all wet
You're all cold
Dripping with alchemy
Shiver stop shivering
The glitter's all wet
You're all chrome
The men cry out, the girls cry out
The men cry out, the girls cry out
The men cry out, oh no
The men cry out, the girls cry out
The men cry out, the girls cry out
The men cry out, oh no
Oh, oh, oh, oh
Off, off with your head
Dance, dance 'til you're dead
Heads will roll, heads will roll
Heads will roll on the floor
Looking glass, take the past
Shut your eyes, you realize
Looking glass, take the past
Shut your eyes, you realize
Glitter on the wet streets
Silver over everything
The glitter's all wet
You're all chrome, you're all chrome
Oh, oh, oh
Off, off, off with your head
Dance, dance, dance 'til you're dead
Off, off, off with your head
Dance, dance, dance 'til you're dead
Off, off, off with your head
Dance, dance, dance 'til you're dead
Off, off, off with your head
Dance, dance, dance 'til you're dead
Off, off, off with your head
Dance, dance, dance 'til you're dead
Off, off, off with your head