> For the complete documentation index, see [llms.txt](https://hackdays-guide.mlh.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hackdays-guide.mlh.com/plan-your-event/attendee-communications.md).

# Attendee Communications

Keep event information accurate and share the local details attendees need to arrive prepared.

MLH already sends registration confirmations and standard attendee reminder emails. Organizers do not need to duplicate them. Focus your communication on practical event details that MLH may not have, especially the exact venue, room, arrival instructions, and local contact information.

## Keep the Event Page Current

Your published Hack Day page is the public source of truth for your event. Before MLH's attendee reminders are sent, confirm that it includes:

* Event date, start time, and end time
* Complete venue name, address, room, and arrival instructions
* A clear statement that the event takes place entirely in person
* A contact email for attendee questions and accessibility requests
* The intended audience and any age or partner eligibility restrictions
* Food and beverage information
* What attendees should bring
* The MLH Code of Conduct

If anything changes, update OrganizerHQ first. Send a separate message only when attendees need to act on an urgent change, such as a different entrance, room, start time, or cancellation.

## Send Event-Details Message(s) When Helpful

Share any event-specific details that are not already clear on your event page, such as the exact room or entrance, building access, parking, what attendees should bring, or who to contact with accessibility questions. Keep each message concise and send it once the relevant details are final.

If you email attendees directly, use BCC so recipients do not see everyone else's email address.

Replace every item in brackets and remove any line that does not apply:

```
Subject: Event details for [Hack Day name]

Here are the details you’ll need for [Hack Day name]. This is a free, entirely in-person event; there is no virtual attendance option.

When: [Day and date, start time–end time, time zone]
Check-in opens: [Time]
Where: [Venue name, full address, room, and entrance]
Arrival: [Transit, parking, security, or building access instructions]
Food: [Meal, snacks, dietary information, or what to bring]
Bring: [Laptop, charger, ID, or other essentials]
Set up before arriving: [Required accounts or tools]

Event page: [Public Hack Day event page URL]
Questions or accessibility requests: [Contact email]
```

## Communicate During the Event

Share operational information with attendees in the room:

* During the opening ceremony, explain the schedule, partner categories, judging process, project deadline, and OrganizerHQ submission link.
* Display the submission link and QR code somewhere visible in the venue.
* Give verbal reminders approximately 60 and 30 minutes before submissions close.
* Make organizers easy to identify so teams can get submission help without leaving the build space.

These are in-person event announcements, not additional attendee emails.

For broader event-marketing and community-growth guidance, use the [MLH Hackathon Organizer Guide](https://guide.mlh.com/general-information/marketing-your-event).