the first two characters in isin code for a security represents
International Securities Identification Number ISINs consist of two alphabetic characters, which are the ISO 3166-1 alpha-2 code for the issuing country, nine alpha-numeric characters (the National Securities Identifying Number, or NSIN, which identifies the security, padded as necessary with leading zeros), and one numerical check digit. They are thus always 12 characters in length. When the NSIN changes due to corporate actions or other reasons, the ISIN will also change. Issuance of ISINs is decentralized to individual National Numbering Agencies ("NNA"). Since existing national numbering schemes administered by the various NNAs form the basis for ISINs, the methodology for assignment is not consistent across agencies globally.
GPS signals To prevent unauthorized users from using or potentially interfering with the military signal through spoofing, it was decided to encrypt the P-code. To that end the P-code was modulated with the W-code, a special encryption sequence, to generate the Y-code. The Y-code is what the satellites have been transmitting since the anti-spoofing module was set to the "on" state. The encrypted signal is referred to as the P(Y)-code.