I can tell you that I was a non select at the SEP09 board, and I applied again at the MAR10 board without a letter of reconsideration, and my package was considered. I was also a non select at the MAR10 board and was told I would need a letter of reconsideration at the SEP10 board. I wondered whether I really needed one, but figured that it's not going to harm my package to have too much documentation. I also see it as an opportunity to provide a personal narrative for the positive changes in your package.
I can tell you this: the March and September IDC boards are indeed 6 months apart, more or less. But the relevant CNRC instruction says that a letter of reconsideration must be submitted if there is less than six months between your
notification of non-select (which I presume would be seen as the date on the results letter) and the date the next board convenes. In the case of the IDC boards, this could be slightly
less than 6 months. I don't know if the board really cares, and clearly they didn't for me in one case.
In any event, here's the instruction:
See
COMNAVCRUITCOMINST 1131.2D, Chapter 5, Reserve Officer Programs Processing:
RECONSIDERATION REQUESTS
Any officer program applicant who has been non-selected may request reconsideration of their application by submitting a request in writing to NAVCRUITCOM (N315). If the request for reconsideration is submitted within six months of official notification of non-selection, the following information must be included:
(1) A new Application Processing and Summary Record (NAVCRUIT 1131/1), with the “Reconsideration” block marked appropriately.
(2) Applicant’s request for reconsideration, including a letter from the applicant stating the reason he/she should be reconsidered for selection. The reconsideration letter must be signed and dated by the applicant.
(3) Any new or updated information including, but not limited to transcripts, interviews and references.
(4) The OPL/OP will update the OTools record.
Applications will not be reconsidered for the same program within six (6) months of non-selection unless new information is submitted that indicates the applicant is better qualified than when previously non-selected or unless changes occur within the requested program’s status (i.e., requested program was previously closed and re-opens).
Note: If more than six months have elapsed since official notification of non-selection, a new application and interviews must be submitted. Original employment references and letters from previous employers need not be replaced. Only references from a new employer are required.