A Pre-proposal is the first 7 day period of any SPS DAO Proposal's life cycle. During this time, discussions about the Pre-proposal should happen and the author can edit the Pre-proposal if they choose to do so. Pre-proposals may be edited by the author during this 7 day period.
Anyone can submit a Pre-proposal to the SPS DAO by transferring 100,000 DEC to null and then publishing a HIVE post from that same account with SPSPROPOSAL as the first tag and putting the transaction ID of the DEC burn at the top of the post. You can find an example Proposal here. If at least 5% of staked SPS votes to support the Pre-proposal it will advance to the Proposal stage after the 7 day Pre-proposal period is complete and no further changes to the submitted Proposal will be accepted.
Additionally, the SPS DAO has voted to empower the SPS Project Manager to create and run community-led Pre-proposals to address ongoing issues or needed changes specifically related to the SPS DAO and the SPS token. For these DAO Sponsored Pre-proposals to be funded and advance to the full Proposal stage, they require that at least 10% of staked SPS votes on them of which a 2/3rds majority must be in favor of the Proposal. If they do not receive at least that level of support, the DAO will not burn 100,000 DEC and these DAO Sponsored Pre-Proposals will not advance to the Proposal stage.