How PAN is formed and how it gets its unique identity?
PAN is a ten-digit unique alphanumeric number issued by the Income Tax Department. The formation of PAN is discussed below :

Out of the first five characters, the first three characters represent the alphabetic series running from AAA to ZZZ. (E.g. ALWPG5809L).
The fourth character of PAN represents the status of the PAN holder (E.g. ALWPG5809L).
"A" stands for Association of Persons (AoP)
"B" stands for Body of Individuals (BOI)

"C" stands for Company

"F" stands for Firm/Limited Liability Partnership

"G" stands for Government Agency

"H" stands for Hindu Undivided Family (HUF)

"J" stands for Artificial Juridical Person

"L" stands for Local Authority

"P" stands for Individual

"T" stands for Trust
Fifth character of PAN represents the first character of the PAN holder's last name/surname in case of an individual. In case of non-individual PAN holders fifth character represents the first character of PAN holder's name (E.g. ALWPG5809L)
Next four characters are sequential numbers running from 0001 to 9999 (E.g. ALWPG5809L).
Last character, i.e., the tenth character is an alphabetic check digit (E.g. ALWPG5809L).

The combination of all the above items gives the PAN its unique identity.