Barhandar 
@Sapphie
The next time, don’t remove the announcement at all, but change the wording every month or so to have people notice “something different on top of the page”, and once the “soft” deadline comes, change it to say that the deadline’s passed but people still have a chance to make late submissions - as you can see, majority only actually do anything when a fire’s lit under their butts, so you can manipulate that to avoid too many people asking for past-hard-deadline submissions*.
*I can guarantee that you’re about to get a few of those.
P.S. Also, accept that there WILL be people who are adamant in their inability to notice text on signs, and that you can’t do ANYTHING for those save for personally notifying them of the collab.
The next time, don’t remove the announcement at all, but change the wording every month or so to have people notice “something different on top of the page”, and once the “soft” deadline comes, change it to say that the deadline’s passed but people still have a chance to make late submissions - as you can see, majority only actually do anything when a fire’s lit under their butts, so you can manipulate that to avoid too many people asking for past-hard-deadline submissions*.
*I can guarantee that you’re about to get a few of those.
P.S. Also, accept that there WILL be people who are adamant in their inability to notice text on signs, and that you can’t do ANYTHING for those save for personally notifying them of the collab.
