You might want to attempt those sections which are most relevant to your research at the moment, and then try the others if you have time. Understanding density modification. Different modes, schemes, and protocols. Reading your output. It is normal to use a reflection file containing every possible reflection to a particular resolution.
Unobserved reflection have records, but a marked with a missing number flag .
This is vital for the preservation of the Free-R reflection, and will be very important in the future as density modification and maximum entropy techniques are used to extrapolate missing reflections. Understanding density modification. Reading Your Output.