A call number is the address of the library item book, journal, DVD....etc.
The first line of the Call Number begins with one, two, or three letters, these letters should be read alphabetically, these letters represents the subject of the item according to LC classification system.
The numbers following the first line letters are read as whole numbers. These numbers may have one or more digits.
A123 will be shelved before A1234. If there are additional numbers after the whole number, these numbers should be treated as decimal AB1234.1 will be between AB1234 and AB1235.
The third part of the call number is a combination of letters and numbers. The numbers are also decimal.
The letters are shelved alphabetically and the numbers following are treated as if they were preceded by a decimal. The numbers in this line of call numbers are read as a decimal number.
0.31 is before 0.68
0.68 is before 0.7
all of the above numbers before 0.754.
The last part in call numbers may include volume numbers. copy numbers, dates of publication,...etc. and other supplement or index specifiers. Examples: V.1 V.2, Vol.1 Vol.2, C1 C2.
The last part of the call number might include not always the location of the item such as HAB which means this items is located in Habshan library or ARZ which means its located in Arzanah library.