If the setting Use positions in BOM lists? has been configured under the heading Preparation under the Manufacturing tab in the Settings procedure, you will also see information about the position at the far left of the BOM list.
The position number allows you to link the row in the BOM list of the preparation to the BOM list of the drawing. Consecutive numbers are used, unless you make a manual change of numbering. If a row is deleted, the rows will not be re-numbered.
Position numbers can also be entered using other denominations, such as C1, C2 etc, which is commonly used for capacitors on circuit boards.
If a preparation is made for a G-part (packaging), the letter "I" is automatically entered by default for inner packaging parts. The following rows are automatically entered as "O" for outer packaging parts.