Some data comes to the DMC in a format other than SEED, such as SEG-Y or SAC. These data are considered "assembled" because they are unique to a project or experiment and are not archived in the same way that the SEED data is archived. Users request this data via e-mail to firstname.lastname@example.org and may request all or part of the data set.
Customized data are data from IRIS DMC that are specifically created to a user’s specifications, which can be by network, station, channel, location code, and time as delimiters. Each user has special needs, and customized requests allow users to get the data they want for their particular area of study. BREQ_FAST is the single best example of a customized request tool, and one that is still most commonly used today.