As meshStack user I would like to provide building block input using a dropdown list with predefined values i.e. server size: Small, Medium, Large or with dynamic values such as: existing landing zones, existing platforms. This feature is crucial for Service platform definition, whenever a user runs a building block and need to specify at runtime a platform or landing zone. To avoid errors and typos this selection must be done from a dropdown list with existing and valid values. Workaround: User needs to have a documentation listing valid values to enter as building block inputs. By doing copy/paste user is not protected from typos, leading spaces, etc. Moreover, the user experience is not optimal as he needs to use two applications simultaneously: documentation and meshStack.