Only listings matching an enabled model reach the board. Type the model as it appears in a listing and the match is built for you, so G3516 also catches G3516B and G3512 catches G3512 LE. Changes apply on the next crawl.
Paste a dealer's web address and the sitemap is found for you. Most sites put listings under /product/; Machinio sites use /listings/. Each site is re-checked every two hours, 18 new pages at a time.