What is developer key?
The developer key is a combination of your installation number, your license key (that you get from http://service.sap.com/licensekey) and the user name. You need this for each person that will make changes (Dictionary or programs) in the system.
To request for a new developer key,
Log on to the URL http://service.sap.com/sscr with your SAP S-user
Click on Register Developer
Enter the user name(s) and select the Installation for which the developer key is required
Click on Register
The key will be displayed in the same screen or you can check from Developer Registered by Me or in DEVACCESS table
Developer access key is nothing but an algorithm based on system number and SID and some other system values (SAP does not reveal the information). The developer access key is validated by SAP using a Kernel level C system program ''CHECK_DEVELOPER_KEY'. So, even if the developer access key has been deleted for a user ID in the DEVACCESS table, user can still use the same developer access key.
if you would like to look up at your developer key and save it and have it available for the next system refresh.
The table name is DEVACCESS and can be viewed with SE16 and SE11.
For new ABAP developer, you will be prompt for the developer if you are trying to create a program using the standard SAP naming convention.
Customer own created program should all start with a "Y" or "Z".