Consider creating a shortcut to the SDK help file: ..\doc\MicroStationAPI.chm.
This file contains verbatim all SDK include files (.fdf, .h and .r.h) allowing quick, convenient, and precise searching to performed quite easily.
From the Search tab you can simply search for a MDL C API function is question or use boolean operators (AND, OR, NOT and NEAR) to quickly narrow in on items needed.
When searching for mdlTex_expandTabs there are two help topic results of primary interest: "deprecated10_0.fdf File Reference" and "Deprecated List". The help topic (or file) name indicates the state of support for the function being deprecated. This means that any new code or code being upgraded should try to find replacement APIs as soon as possible, since at some point deprecated functions will be removed and no longer accessible for older applications. The "Deprecated List" help topic provides the useful information below on the current function signature required, and optionally provides indications for new API replacement options.
Member mdlText_expandTabs (WStringR outstring, WCharCP instring, int tabInterval) This utility has been deprecated, with no direct replacement. When dealing with text elements, the TextBockAPI can handle tabs (see AppendTab; and ParagraphProperties for tab settings), and should be used instead of faking alignment with spaces.
When searching the SDK examples directory you can find a code sample using the new API here:
Annotations\TextExample\TextExampleData.cpp:41: textBlock.AppendTab();
HTH,
Bob