A presolicitation notice tells the market that a specific requirement is on its way, sometimes with an expected NAICS code, set-aside decision, or release date, before the full solicitation package is posted. It is not itself something you respond to with a proposal; it is a heads up to start preparing, teaming, or asking early questions if the notice invites them. Not every requirement gets one, and the actual solicitation can still shift from what the presolicitation described.

In a sentence

"The solicitation is anticipated to be posted within 30 days of this presolicitation notice." That is your cue to start lining up teaming partners and past performance examples now, before the clock on the real deadline even starts.