Question on EDF T&Cs for Blue+Price Promise March 2015

shews

Dear all,

In EDF's Blue+Price Promise 2015 T&Cs, clause 12 states:
my.edfenergy.com/pdfs/1/tariff/59
(as a new user I can't post links, hence you can't click it)

To avoid any doubt, we will not increase your price
until 31 March 2015. However, we will be allowed to
change any other part of Blue+Price Promise March 2015
full tariff rules at any time by publishing the amendments
on our website. All these changes will apply from the date
we publish the change on our website. If, by law, we have
to make any significant changes to the full tariff rules, we
will let you know about the changes in writing and in line
with the conditions of our supply licence. We can
withdraw the Blue+Price Promise March 2015 tariff from
sale at any time by telling our customers about this on our
website. We will not accept any applications we receive
after this date.

I take "If, by law" to mean changes initiated by government. Fair enough.

What does "allowed to change any other part" actually entail?

Changing the end date?
Adding extra admin/other charges?

A friend mentioned their "price promise" was reneged on; though I've not yet got details of who their supplier was and when this happened. it was British Gas and "the circumstances were apparently beyond their control"

Thanks to anyone who can shed some light,


Shews