abap/unicode_check is a SAP Parameter attribute which is used to control Unicode check for ABAP programs 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 .
The parameter ABAP/UNICODE_CHECK controls Unicode checks during the
syntax check and while ABAP programs are running in NON-Unicode systems.
The parameter can have one of the following values:
The Unicode checks are run for each ABAP program. The system then
behaves as if the program attribute "Unicode Checks Active" were s
elected for all ABAP programs.
No Unicode checks are performed.
The Unicode checks of course always run in Unicode systems, regardless
of the value specified for the parameter.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.