"dilution in steps of 1 to 100 (centesimal); indicated by C or CH"

Homeopathic dilutions are prepared according to the Hahnemannian method. If the successive dilutions are by tenths (one part of substance to nine parts alcohol), they are called decimal solutions. They are labeled by the letter X or D, sometimes followed by H (Hahnemann). Thus, a third decimal solution would be specified as 3X or 3D. If the successive dilutions are made to one-hundredth they are called centesimals.

They are denoted by the letters C or CH or they carry no notation. The dilution (potency) being given and the specificity of action discovered, the potentized substance should be as pure as possible.
www.longnaturalhealth.com/library2.asp?A=55

Homeopathic dilutions are prepared according to the Hahnemannian method. If the successive dilutions are by tenths (one part of substance to nine parts alcohol), they are called decimal solutions. They are labeled by the letter X or D, sometimes followed by H (Hahnemann). Thus, a third decimal solution would be specified as 3X or 3D. If the successive dilutions are made to one-hundredth they are called centesimals. They are denoted by the letters C or CH or they carry no notation. The dilution (potency) being given and the specificity of action discovered, the potentized substance should be as pure as possible. No one should "contaminate" the solutions made. Each dilution is energetically agitated: this is the "Dynamization process". These dynamized solutions to one-tenth or one-hundredth, serve as base for preparing homeopathic medications.

The dilution factor at each stage is traditionally 1:10 ('D' or 'X' potencies) or 1:100 ('C' potencies). Hahnemann advocated 30C dilutions for most purposes, i.e. dilution by a factor of 10030 = 1060. As Avogadro's number is only 6.02 × 1023 particles/mole, the chance of any molecule of the original substance being present in a 15C solution is small, and it is extremely unlikely that one molecule of the original solution would be present in a 30C dilution. For a perspective on these numbers, there are in the order of 1032 molecules of water in an Olympic size swimming pool; to expect to get one molecule of a 15C solution, one would need to take 1% of the volume of such a pool, or roughly 25 metric tons of water. Thus, even homeopathic remedies of a high "potency" contain, with overwhelming probability, only water. Practitioners of homeopathy believe that this water retains some 'essential property' of one of the substances that it has contacted in the past.

Answerer's editorial comment: Speaking as one trained in science, do you not consider it unethical to even translate such crap?