How to get access to Header Section instances using SDAI?

Two following SDAI extension functions are declared in sdai.h header:

SdaiInstance _sdaiHeaderDescription(SdaiRep repository);
SdaiInstance _sdaiHeaderName(SdaiRep repository);

Then attribute values of instances can be accessed using standard sdaiGetAttrBN/sdaiPutAttrBN functions.

The third instance of FILE_SCHEMA type can’t be accessed and is filled automatically when writing repository to file.