The link takes you to the FIDE laws as modified for competitions starting after 1st July 2014.
In general, Sheffield Association chess is played according to FIDE rules, but any Rules or decisions of the Association which contradict the FIDE rules may override them.
In particular (and as an example), the new FIDE rules under Article 11.3, which include the rule:
11.3(b) During play, a player is forbidden to have a mobile phone and/or other electronic means of communication in the playing venue. If it is evident that a player brought such a device into the playing venue, he shall lose the game.
was considered unsuitable for Association matches by the Fixture Meeting on 16th September 2014. See the Mobile Phones page for details.