abap/collation/icu_sortkey_factor is a SAP Parameter attribute which is used to control size of internal ICU sortkeys 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 only applies in Unicode systems. The ABAP commands SORT
... AS TEXT and CONVERT ... INTO SORTABLE CODE use internal fields in
which a binary, sortable code is stored. If these fields are too small,
the sorting can become imprecise. You can avoid this by increasing the
parameter value.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.