On the main page of the SYSTEM, you can sort and search for items by various criteria (price, date, the presence/absence of an image, etc.).

   The drop-down list `Seller` displays the numbers of only those sellers who have placed at least one item online.

   The drop-down list `Category` displays only those categories that contain at least one item, placed online by any of the sellers.

   If a specific seller`s number is selected in the drop-down list `Seller`, in this case the drop-down list `Category` displays only those categories that are used by this seller and that contain at least one item placed online by this seller.

   If a specific category is selected in the drop-down list `Category`, in this case only those sellers who have placed at least one item online in this category are displayed in the drop-down list `Seller`.

   Each item in the SYSTEM has its own unique number. To find the item it`s enough to enter its number in the search box `Find an item by number` and click `SEARCH` (the search is performed only among the items placed online).