If there’s a chance that readers won’t recognise an abbreviation or acronym, spell it out the first time you mention it and specify the abbreviation in parentheses. Then use the short version for all other references.
- First use: World Economic Forum (WEF)
- Second use: WEF
If the abbreviation or acronym is well-known, like MiFID II or IPO, you can use it without spelling it out.
Do not use full stops when using abbreviations.
- Yes: WTO
- No: W.T.O.