Table 1 Structure of the Inventory Form

1 Localization

Free field

Identification and localization of the specific element of the city walls

2 Characterization

2.1 Historical characterization

Restricted choice field

Knowledge of the time of construction and the time of the main modifications undergone

2.2 Morphological characterization

Restricted choice field; free field

Knowledge of the type and function of the element within the city wall and its specific dimensions

2.3 State of conservation documentation

Multimedia resources field

Collection of existing surveys and documents that witness construction phases, modifications, failures that occurred in the past, and current and past state of conservation

3 Accessibility for technical inspections and visitability

Restricted choice field

Assessment of the possibilities of inspection to prepare suitable means and equipment that ensure the safety of inspectors or to provide measures that guarantee inspectability of the portions where maintenance is not currently carried out

4 Documentation of interventions

4.1 Intervention archive

Free field

Collection of restoration interventions undergone by the element

4.2 Conservation state and maintenance

Restricted choice field

Evaluation of the state of conservation and maintenance needs for the element

5 Material archive - masonry typologies

Free field; multimedia resources field; restricted choice field

Identification of masonry type and materials of the element

6 Description of the context and hazards

Restricted choice field

Identification of specific hazards for assessing their impact on the structure

7 critical conditions to activate diagnosis or safety measures

Restricted choice field

Assessment of the need to improve the knowledge of the element or to resort to more or less urgent safety interventions