How to use rsync to synchronize two folders without overriding permissions

Very popular and easy to remeber rsync command is rsync -a source_dir target_dir . "-a" is equivalent of "-rlptgoD". What does it mean?? Let's analyze it step by step.

• "-r" - reqursive
• "-l" - copy symbolic links as symbolic links
• "-p" - preserve permessions
• "-t" - preserve modification dates
• "-g" - preserve group
• "-o" - preserve owner (works only with root account)
• "-D" - preserve device files and special files

So to do the same as "-a" does we need to ommit "-p" switch.

rsync -rltgoD m/bdg .