iPhone App Info->Identifier

from iPhone Dev Center

Example App ID: A1B2C3D4E5.com.domainname.applicationname
Identifier to enter in Xcode: com.domainname.applicationname

Example App ID: A1B2C3D4E5.com.domainname.*
Identifier to enter in Xcode: com.domainname.${PRODUCT_NAME}

Example App ID: A1B2C3D4E5.*
Identifier to enter in Xcode: ${PRODUCT_NAME:rfc1034identifier}