This product-specific custom field is displayed above the price in the product box on listing pages and/or in the buy box on the product page.
The input field is HTML-capable, but be careful with the formatting.
Note: You can enable/disable the "Short description" in the theme configuration.
You can find the "Short description" custom field in the respective product:
Tab "Specifications" ⇒ Block "Custom fields" ⇒ Tab (Set) "Products (ThemeWare® ... Pro)"
Type: Text editor (HTML)
Technical name: twt_{theme}_{edition}_custom_field__product__short_description
You can find more information about the "Product short description" extension here: