There is different between part number in datasheet and what is sold in store.for example:
in datasheet we have only:
but is store we have:
How can I understand what are exactly these extended character meaning? is there any reference?
In the examples you gave above, there is no difference in the individual parts. The -RL7 indicates that the parts will be delivered in a 7 inch tape and reel and minimum quantity is 1500 pieces. For lower quantities, part should be delivered in a tray.
I see in the datasheet, the ADF5904 comes in an Automotive Qualified model: ADF5904WCCPZ, which is designated by the "W".
"Z" designates RoHS compliant parts.
See the Ordering Guide in the last page of the datasheet for more information.