Quota column - to define how many times an option can be selected before it should disappear.Note: these cells are formatted as Plain text to prevent the apps script from trying to convert them into a fully defined date string. Options column - a list of the time slots that is used to recreate the multiple choice list on the Form after submission.The Form response sheet has a couple of extra tabs added to it - one of those being Options - which contains: This is achieved via apps script running in the Form response sheet to recreate the multiple choice list on the Form after a submission, with only the available options left - based on their quota allowance. The principle is simply that a user would select their desired appointment slot on the Form and then that option would be unavailable for the next user accessing the Form. I am aware there are a number of Google add-ons that achieve this but they come with potential data protection issues when accessing your Google Account, hence an in-house approach. The following Google Apps Script code was developed as I wanted to learn about removing Google Form option choices as part of exploring its capabilities for use with appointment slots.