Items in other DocTypes


my primary question is:
Why are my items not shown in DocTypes like “Maintenance Visit” or “Opportunity”. But when I create one document in “Opportunity”, it is linked with the product table…unfortunately the Maintenance Visit is not linked to “Items”


There is a item table in Maintenance Visit document as well.

Yes, but the prob is that it wont link to the item table…

It links to item table, may be you have modified options value for the item_code field.