not "underway"

United Nations Educational Scientific and Cultural Organization

Not "Unesco"

Acronym doesn’t need spelling out for the CERN Courier

All SI units are lower case when spelled out: metre (m), kilogram (kg), second (s), ampere (A), kelvin (K), candela (cd), mole (mol).

Note: The tesla is the SI-derived unit of magnetic flux density. It has a lower-case "t" when spelled out, though its symbol is an upper-case "T".

Spell them out on first mention, then use the symbol.

I weigh 75 kilograms. Last month I gained 4 kg after I stopped running 5 kilometres every morning.

Upper case when referring to our Universe, otherwise lower case 

Where it is useful to advertise a URL (in printed materials, for instance) use the following format: cern.ch/[sitename]

Example: cern.ch/writing-guidelines (note that this resolves to test-static-04.web.cern.ch, which is less easy for new users to remember).

Notes

use hyphen