43 CFR §2.54

1. (a)The bureau may aggregate requests and charge accordingly when it reasonably believes that you, or a group of requesters acting in concert with you, are attempting to avoid fees by dividing a single request into a series of requests on a single subject or related subjects.
   1. (1)The bureau may presume that multiple requests of this type made within a 30-day period have been made to avoid fees.
   2. (2)The bureau may aggregate requests separated by a longer period only where there is a reasonable basis for determining that aggregation is warranted in view of all the circumstances involved.
2. (b)The bureau will not aggregate multiple requests involving unrelated matters.
3. (c)The bureau may administratively aggregate requests without charging fees accordingly when it reasonably believes you, or a group of requesters acting in concert with you, are dividing a single request into a series of requests on a single subject or related subjects.
   1. (1)The bureau may presume that multiple requests on a single subject or related subjects made within a 30-day period are dividing a single request into a series of requests.
   2. (2)The bureau may administratively aggregate requests separated by a longer period only where there is a reasonable basis for determining that aggregation is warranted in view of all the circumstances involved.