You want to understand how Text Identification is done in SAP Query.
As of release 45B a method for identifying text is available in the query. In this release, this method only works in infosets based on logical databases PAP, PCH and PNP. This method determines the field text based on the DDIC information for the field (check tables, value tables…). However, sometimes is not possible to determine a text using this procedure. For these cases, it is possible to get the text using a function module. This is done in customizing table T770T. In this table, you have to enter the infotype structure name (Pxxxx), the field name and the function module that is going to be used to get the text. This function module has to have an specific interface (please use as template function module RH_TEXT_GET_TEMPLATE). So using this table it’s also possible to create exceptions, but only at field level.
As of release 46C a general method for identifying texts is available (not only for HR logical databases). It also evaluates the text based on DDIC information. Using this method it is possible to create exceptions for text retrieval not only at field level (via customizing table TEXC_FLD), but also at data element level (TEXC_DE) and domain level (TEXC_DOM). In case a text could be evaluated using these three tables (an entry in table TEXC_FLD for the field name, an entry for the data element in table TEXC_DE and an entry for the domain in TEXC_DOM), table TEXC_FLD will be the highest priority, followed by TEXC_DE and finally TEXC_DOM.
As of this release a report is also available to get where the texts are retrieved (check table, function module….). This report is called RS_TEST_IDENTIFY_TEXT. Running this report for the structure using the Text Recognition for HR class, you are able to get information about if the text is readable for the field or not, where the text is coming from and if an exception exist for that field.
Note: text retrieval in SAP query is a generic method and does not check authorizations. So if the user can display the field value in the query, he/she will be also able to display the text there.