Merge Changes into SDL-Delivered Code

If you isolate customizations to delivered code, it is simpler and more reliable to merge custom changes into any delivered files. The developer is more familiar with his/her own code and is more careful about merging his/her code into foreign code. It is easier to miss a small but significant SDL change if a merge is attempted the other way.

The process of isolating customizations to delivered code is explained in Step 2: Isolate Customizations to Delivered Code.