Yes, there are two options for additonal fields

Option lists (menu option Rescue Organization Manager -> Option Lists)

If the field is for a defined set of options create an option list, an option list can be defined as a single select list (i.e. radio buttons) or a multi select list (i.e. checkboxes).

Fields (menu option Rescue Organization Manager -> Fields)

This feature provides for fields of type single line text, multi line text date, date & time, currency, number or phone number.

When adding a custom field or list you define which section (tab) on the edit page the field is displayed on and by creating your own custom groups (menu option "Rescue Organization Manager -> Data Groups") you can add you own sections (tabs) to the edit pages.

Custom fields or lists can be added for members, contacts, assets, events, participants added to an event, assets added to an event, event claims, event subjects and event teams and the same field or list definition can be used on one or more to prevent the need to create duplicate fields or lists.