Only two days remain until the Women’s March on Washington Saturday (January 21). 

The Facebook event lists more than 200,000 people who will attend to send incoming president Donald Trump a message, including celebrities America Ferrera, Uzo Aduba and Zendaya.

While some people (like writer Jamilah Lemieux) have opted to skip the march, anyone going needs to know what they should—and can’t—bring and what to do if law enforcement decides to act aggressively.

Self-proclaimed “Black girl trouble-maker” Brittany Brathwaite gave an extensive, extremely useful breakdown on a Medium post, from which Colorlines has pulled.

The basics

• Appropriate clothing for winter in the Northeast. This means hats, scarves, gloves, layers. Oh, and warm, flat, comfortable shoes—you will be walking after all.
• Download this list of where to warm up, rest and take a bathroom break.
• Cash. You can’t expect every vendor to have a Square card reader.
• A tiny bag. The march doesn’t permit anything larger than 8”x6”x4” unless it’s clear. If it is clear, it can be 17”x12”x6”. No larger than that. An additional 12”x12”x6” plastic or gallon bag also will be allowed for anyone bringing lunch from home, which is recommended.
• Water, water, water.
• Snacks, snacks, snacks. Because who can walk around for hours without something to munch on?
• Moisture. If your skin is sensitive or dry, bring lotion or coconut oil to hydrate. Lip balm will also help fight irritation from the cold.
• Chargers. Even if you don’t need it, others could use your phone charger. Staying connected is key on Saturday.

Safety

• Sharpie. In any protest setting, participants can’t anticipate what will happen. Use the Sharpie to write the march’s legal hotline number (202-670-6866) on your arm. Feel free to add any other important contact numbers you’d forget if police confiscate your phone, as well as medical issues or allergies. The Sharpie can also be shared with fellow marchers.
• Read this Colorlines article that breaks down what to do if police do arrest you. Due to implicit bias, you’re more likely to be arrested if you’re a person of color. If you’re a trans person, be prepared to be incarcerated with a gender with which you do not identify. In short: be sure you want to risk arrest, shout your name if you’re being arrested so that legal observers can write it down, have people with you, do not resist and ask for an attorney.
• Safety plan. You need to know where you and your friends will meet if anything happens. A couple of people not attending the march should also have a general idea of where you’ll be in case of an emergency. 
• Immigration defense attorneys. Undocumented immigrants need to exercise even more caution, but march organizers will have a team of attorneys on site just in case. They can be reached at the legal hotline number above.
• Stay to the edges of the crowd. This will make it easier to evacuate if things escalate or you need to rest. People of color will likely be the first target if police decide to do mass arrests.
• Personal information. This might sound obvious, but don’t give it out to strangers because they could publicly share it or, if they’re a White supremacist organizer, hand it out to their colleagues. If someone wants to connect with you, consider giving them a Twitter handle or email address. Don’t give a phone number until you can vet them.

The march starts at 10 a.m. ET on the corner of Independence Avenue and Third Street Southwest. Check the website to find a bus, buy Metro cards or join a local march if you can’t make it to D.C.