On the 10th December the government published a new 'How to rent in England' leaflet. 

Remember if you are signing any new tenancies, or issuing any new fixed terms agreement on or after this date you must make sure you provide the most up to date version.

the new version include details of the new Electrical safety requirements. 

If you don't provide the correct version of the leaflet you will not be able to serve a valid section 21 notice should you need to ask for possession of the property in the future.  Make sure you delete any old copies  you may have downloaded and held on file to avoid mistakes!