abap/import_char_conversion is a SAP Parameter attribute which is used to control Automatic conversion in ABAP-statement IMPORT 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 .
This parameter specifies whether the character strings are to be
converted automatically in the ABAP statement IMPORT. The parameter
should normally have the value 1, which means the conversion takes place
automatically. (This refers to the conversion between different code
pages.) Customers who work with several character sets in their system
can set the parameter value to 0 if configuring their R/3 system for
multi-NLS. (In this case, conversion does not take place automatically.)
In more specific cases, a value of 2 is also possible with this kind of
configuration. The value 2 means that conversion does not normally take
place (as with the value 0), except in the case of code page
combinations where the characters A-Z, a-z, 0-9 have different locations
(for example, in ASCII<(><<)>->EBCDIC combinations).
See SAP Parameter Documentation for full SAP documentation for this profile parameter.