abap/deferred_generation is a SAP Parameter attribute which is used to control Enables/Disables deferred generation within ABAP generation information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
Preparation for future development. Do not use. Enables special mode of
ABAP load generation that allows to delay the creation of some special
declaration entries in the load tables. This is a prerequisite for the
use of precompiled headers in generation.
Feature is not yet implemented.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.