There are 2 different passphrase-to-WEP-key creation buttons because the wireless industry uses 2 different methods for converting passphrases to WEP keys.   The first method is primarily used with products based on Intersil technology. This method uses a simple mathematical algorithm to generate WEP keys from a given passphrase. The WaveRunner Generate button uses this method.   The second method, used primarily with Symbol, Intel and Agere (Orinoco) products, simply uses the ASCII representation of each passphrase character to create the WEP keys. If necessary, passphrase characters are reused until enough hex codes have been generated to complete the WEP key. The WaveRunner Alphanumeric button uses this method.