Some characterisitic language used in the description of symmetries
existing or lacking in physical law seems to be rather misleading. For
example:

"The essence of Charge Parity (CP) is the concept of
symmetry. Both C and P are symmetries that are
conserved in most particle interactions."

"C represents swapping the electric charges of all the
sub-atomic particles in an interaction; in other words,
swapping particles and antiparticles. P is called parity
and it corresponds to looking in a mirror that reverses
all three spatial co-ordinates."

http://news.bbc.co.uk/1/hi/sci/tech/1330190.stm

The symmetries are said to be "conserved", but the conservation of a
physical quantity is not implied; there is no conserved physical
quantity called "parity". It so happens electric charge _is_ a
conserved quantity, but this merely adds to the confusion. What is
meant is that physical law is either invariant in form, or not, under
the reversal of charge or coordinates.