The Select title block step of the Extraction Template wizard enables you to specify where in the title block the information critical to the BOM is placed.
The rules that the wizard discovers is later saved to the extraction template. The BOM Extraction wizard uses these rules to extract information from the title blocks of the drawings it migrates.
The wizard requires you to select the title block in the current drawing, and point to the cells that contain information critical to the BOM. The wizard then extracts the text from the selected cells and lists them in the Extracted text objects list.
What if a cell that is supposed to contain information critical to the BOM is empty in the current drawing? You select the cell even though it is empty. The wizard assigns a name such as TEXT# to it after extracting. Later on, you can rename it in the Extracted text objects list.
If the title block was created using the AMTITLE command the wizard intelligently extracts values and ignores labels/captions. If the title block was created by other means, the wizard blindly imports all text from the selected cells. The wizard then displays the 
icon in front of such text objects. You then select each such row and click the Fine tune button. The wizard then displays a dialog box, where you can point to the extracted labels/captions and instruct the wizard to ignore them.
In a subsequent step of this wizard, you map the extracted text objects to the corresponding component properties. Hence each row in the Extracted text objects list must match to exactly 1 component property in the BOM.
What if a row in the Extracted text objects list contains the values of more than 1 component property? You select the row and click the Fine tune button. The wizard then displays a dialog box, where you can split the text into multiple rows.
When each row in the Extracted text objects list matches exactly 1 component property, you are ready to proceed to the next step.