SNOTE

SAP Help on SNOTE : LINK

Reading SNOTE
First check the Support Packages and Patches

Software Components
It is the latest pack/patch where the note has been applied. 
Any system which is equal to or above the mentioned support packages will already have the note applied , generally. No need to apply the note

Correction changes can be applied by directly downloading the Note in the system, or in some cases, some coding changes need to be done or parameters needs to be maintained manually.

Checking Support packages in SAP
In any SAP window Goto 'System' --> Status --> Component Version.
Here you can find
Software Component | Release | Level | Highest Support Package | Short Description. in ECC

Component | Release | SP-Level | Support Package | Short Description of Component in BW

Below is how you can see NOTES in SNOTE.

The ones in greyed out diamond are with status 'cannot be implemented'.

When you get message status "Cannot be implemented" means the code related to note is already exists in your SAP version. Just go to change instruction and see the changes come with the note and change the same object in your SAP system. The changes mentioned in the Note will exist in your system. Hence, you cannot implement the note or note is not valid for your SAP version.

Implementing SNote

Check if you can see the note in New. If it is not available, GoTo-->Download Note.

Now you can see the note in 'New'.

The ones in BLUE can be implemented. 

Select the Note and Goto SNOTE in Menu ->Implement SNOTE

System will give pop ups asking us to confirm is the user is ready to implement the note. If yes, SAP installs it 
and these changes can be collected in a transport request to move to other systems.

After successful implementation, you can see the note in 'In Processing' status.