Ideally you present your data in our format CIM (Communication and Information Model). This format is open, lightweight (JSON) and very easy to understand.
The format already contains a wide range of attributes from different areas of communication data (Telephone Communication, IP, Social Media, Radio Interception etc) which can be easily extended by using generic attributes.
The minimum requirement is a time-stamp and some form of identifier to enable an “Event” to be created. Additionally, you can set coordinates to specify an exact location with anything beyond that (e.g. text, attachments) easily added using the specification with the software then providing different tools to visualise this Data.
Besides “event-based” data you can also integrate knowledge data as “Actors” (Name, Surname; Addresses including phone numbers, e-mail, IMEI, account information; and further information specifying the person and the source of information). Actors can either be related to other actors or events.