In addition to the information I gave here http://scn.sap.com/thread/3521328
Here is the guide
https://websmp208.sap-ag.de/~sapidb/011000358700000849422013
Read the chapter 1.1 Naming Conventions. There you have the "Usage of Release Names" with a table provided. EHP3 for SCM is based on NW 7.4 release
How this upgrade can be done..Should I have to upgrade to 7.4 first from the 7.0 and then to EHP3? (or) Simply can I do SCM 7.0 to SCM 7.0 EHP3 as normally?
This is a normal single upgrade. You just need to upgrade the SCM 7.0 to the EHP3 using the SUM tool.
Is this NW 7.4 concept introduced from SCM 7.0 EHP3 or available with SCM 7.0 EHP2 itself..Kindly correct me If am wrong anywhere
Go through the table shown under "Usage of Release Names"
Please clarify my doubts and tell me which option should I do choose in the attached screen for SCM 7.0 EHP3 upgrade for media download and proceed
if you are doing an upgrade first get a stack file generated and then download those packages and the kernel files for the upgrade.
Regards
RB