Election data should be available via a stable internet location for an indefinite period of time. In the Open Data Policy Guidelines, permanent data is defined as available through a "stable online location" or through "archives in perpetuity." Data that is only available for a short period of time is not open. One way to ensure that datasets are permanently available is to provide them with permanent web addresses (i.e., a permanent URL). Permanent and stable web addresses help the public access the data and share the data with others by pointing them to the direct (and unchanged) source. Datasets from previous election cycles can be especially useful in understanding and evaluating the current election cycle. Elections datasets, much like datasets on government spending, are often directly comparable to previous (i.e., historical) datasets. Election monitoring organizations have a history of taking a current election dataset, such as voter registration, campaign finance or election results, and comparing it to a historical dataset as one way of evaluating the quality of the data. Thus, permanence is a necessary requirement for a "current" dataset to become a "historical" dataset. If a dataset disappears, it is no longer available for use; if the data cannot be used, it is not open. One of the more practical ways an EMB can make election data permanent is to make sure the data is published in a public data portal or in an online archive.