While and Although

0While the transmittal letter is not an appendix item, it often emerges as a last-minute detail when the proposal narrative and appendixes are assembled.02br
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00While proposals are seldom rejected because of shortcomings in the appendixes, the reviewers nevertheless do expect to see certain information items properly presented.02br
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00While congressional officials will usually provide such letters when requested, use them sparingly; that is, save congressional “muscle” for big projects, not routine ones.02br
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00Can "while" be substituted with "although" in the above sentences. Please advise.0-