(         TBL_SOURCE    as table, 
 optional S_RENAME_TAG  as nullable text,
 optional B_DO_RENAME   as nullable logical) as table => 
    let
        RenamingNeeded = if B_DO_RENAME  = null then true else B_DO_RENAME,
        RenameTag =      if S_RENAME_TAG = null then ""   else S_RENAME_TAG,
        
        InitialColumnNames = Table.ColumnNames(TBL_SOURCE),
        RenameTableColumns = if RenamingNeeded then
                                let
                                    NewColumnNames = List.Transform(InitialColumnNames, each fReplaceFunction(_, true, S_RENAME_TAG)),
                                    RenameColumns = Table.RenameColumns(TBL_SOURCE, 
                                                                        List.Zip({InitialColumnNames, NewColumnNames}))
                                in
                                    RenameColumns
                             else
                                TBL_SOURCE,
        
        ColumnsToKeep = fGetNeededColumnNames(RenameTag),
        KeepNeeded = Table.SelectColumns(RenameTableColumns, ColumnsToKeep, MissingField.Ignore)
    in
        KeepNeeded