If the topics is closely connected to one of the IUCr commissions then the best way is to contact corresponding representative in the International Programme Committee (see list with commissions and list with contacts). It is always good, if some more comments are sent than just a title. E-mail can also be sent to the IPC chair - Ivana Kuta Smatanova (programme et iucr2020.org).
Deadline, March 1, 2019
You can send suggestions after the deadline till May 5 but with time the chance of their acceptance is decreasing
This can be discussed with the corresponding IUCr commission. The person responsible for coordination of these events is the chair of National Advisory Board (AB) - Jindrich Hasek (hasekjh et seznam.cz).
Deadline, September 30, 2019
Questions, comments etc. can be sent to Martin Haloun (PCO Auletris) - exhibition et iucr2020.org. Booklet for sponsor and exhibitors is in preparation.
Any of the above suggestions or comments can also be sent to the congress chair
Radek Kuzel (chair et iucr2020.org).
General conference e-mail: info et iucr2020.org