12 CFR §192.310

1. (a)In general. A savings association must file a post-effective amendment to the offering circular with the appropriate Federal banking agency or have its proposed stock holding company file a post-effective amendment to its registration statement for the offering circular with the Securities and Exchange Commission, when a material event or change of circumstances occurs.
2. (b)Timing of delivery. After the appropriate Federal banking agency or the Securities and Exchange Commission declares the post-effective amendment effective, the savings association must immediately have the amendment to the offering circular delivered to each person who subscribed for or ordered shares in the offering.
3. (c)Content. The post-effective amendment must indicate that each person may increase, decrease, or rescind their subscription or order.
4. (d)Post-effective offering period. The post-effective offering period must remain open no less than 10 calendar days nor more than 20 calendar days, unless the appropriate Federal banking agency approves a longer rescission period.