All About MIDlets - Beginning J2ME: From Novice to Professional - page 36

Multiple permission types are placed on the same line, separated by commas.
If your MIDlet suite does not need certain permissions to function, but it may use them for
enhanced functionality, these permissions can be placed in the MIDlet-Permissions-Opt attribute.
At installation time, the application management software will compare the permissions
requested in the descriptor with the permissions in the destination protection domain. If there
are irreconcilable differences, the MIDlet suite will not be installed.
Summary
MIDP applications are called MIDlets. Like applets or servlets, MIDlets have a specific life
cycle; they are managed by device software. This chapter detailed the entries that must and
may be in the MIDlet suite manifest file and the application descriptor. Application properties
can be used as a way to store information in the application descriptor instead of hard-coding
values into the MIDlet source code. A tool like the J2ME Wireless Toolkit automatically handles
many of the details of MIDlet attributes packaging. MIDlets enjoy a comprehensive security
architecture based on protection domains.