The genetic symbols here are separated into groups by their effects and know linkage. These groupings of genes are listed here along with their mutated alleles.
All genes shown in upper case are dominant.
All recessive genes are given in lower case. This case distinction between the dominant and recessive types is a standard practice to aid in keeping them properly classified in ones mind. Just remember, if its listed as beginning with a capital letter, it's a dominant gene. A dominant gene will always express itself when not being masked by another, more dominant or modifying type gene. Symbols beginning in lower case are always recessive.