The majority of research disciplines have national archives which are well known to the community; however, if your subject does not have an archive you may use the University of Hertfordshire Research Archive to preserve your data.
The openDOAR database contains links to thousands of repositories around the world and can be used to search for subject, institutional, and national archives. We recommend that you use this service to identify possible repositories if you are not obligated to submit your data to a specific repository by your funding body. You should be aware of these repositories when you apply for funding as they are valuable sources of data that may aid your research so should be considered when completing your Data Management Plan.
The University of Hertfordshire Research Archive (UHRA) is a catalogue of publications that involve UH members. E-prints of these publications are available for download. The UHRA also includes a data catalogue recording the location of data related to the publications, and where national and international subject repositories are unavailable, datasets@UHRA can be used to preserve your data.
The term "Open data" is unsettling and can have different connotations depending on who you talk to. Generally, it means that data is accessible by everyone. With respect to repositories, it is unreasonable and unlikely that all data is available without restrictions.
Sensitive data may only be available to researchers affiliated with a University, or it may only be available to accredited users as the consent may only be for reuse within research.
Data that is yet to be published may be unavailable for a period of time after it is collected; this is known as proprietary data or embargoed data. When the data are stored at a facility, such as an observatory or the NERC data centre, the principal investigator who requested the observation or measurement has the right of first use which invokes an embargo period. If data is being collected for a post-graduate research student's thesis, these data may be retained and embargoed to allow the student to publish their thesis. Data may also be embargoed if a patent is being applied for.