Suggesting an amendment to the related Jira case #25478 since:

• The grid construction as it stands does not work well with form fillers that do not support itemControl='grid' because of the vertical bar in the item.text
• The existing itemControl codes 'atable', 'gtable' and 'table' works fairly well even if the form filler do not support those item codes

I believe the following amendment would also be compatible with form fillers that do not support itemCode='grid':

A group section marked with itemControl='grid' indicates that child items of type='group' within the grid-section are rows, and questions beneath the row-groups are organized as columns in the grid. The grid might be fully populated, but could be sparse. Questions may support different data types and/or different answer choices.

See a psuedo code example at: https://chat.fhir.org/#narrow/stream/179255-questionnaire/topic/itemControl.20gtable/near/186384795