How to tell guests what is acceptable to wear to the wedding....

You don't tell adults how to dress. Semi-formal doesn't mean anything.

You don't... You don't tell adults what to wear. You let them be adults and figure it out.

Nope, you've done what you can. I told everybody to dress relaxed, as they would for a bbq for my wedding, and plenty showed up in slacks and collared shirts/dresses. You can suggest, but they'll wear what they're gonna wear.

You can't. They will wear what they want.

Ugh no. Don't say anything at all. I hate attire instructions.

Unless your venue has a dress code, you cannot. You can provide a link to your venue so people can know where it is and what it looks like. Your invites will also indicate the formality of the event.

You do not put "Black Tie" on your invites unless it is a true black tie event.

You can't tell them what to wear. True black tie being the exception or if you want to make a note on your website for comfort purposes. Such as suggesting flats at an outdoor wedding. You can try using a more elegant invitation to set the tone though.

You have a couple of options:

1). put on the invite exactly how you expect them to dress which is INCREDIBLY RUDE

2). accept that they are adults and know how to dress them selves AND accept it if it doesn't meet your standards

3). decide not to invite those guests who you think may not adhere to your dress code (also really mean).

Go with 2 if you don't want to hurt feelings/cause problems/be rude. Because if you choose 1 or 3, that is exactly what will happen.

eta: correction

"Attire: Semi-Formal" is fine. Hopefully they'll comply!

What do you mean by visual aids? I'm picturing a picture of someone with a Tshirt with a big red X over it.

You can't tell adults what to wear and honestly if they are the kind of people to wear jeans to a wedding, they will do it regardless of the directions you give them. All you will get from assigning a dress code is pissed off extended family wearing the jeans you expressed weren't good enough for your event.

You definitely can't tell people what to wear! What does it matter aren't they there because you love them and want them to share this day with you?

You don't. Let adults be adults.

You don't. If people show up in jeans, they show up in jeans.

Visual aids lolz

You don't

Listen, Listen, Listen Linda, Don't.

You let them be adults. The only time a reminder about attire was appreciated was black tie/white tie events and even then you can usually tell by the formality of the invitations and such.

Just mention "Suggested attire: semi-formal" and they can look it up if they want. Keep in mind, even if they show up in jeans and a tee-shirt, it's on them. If they are concerned about underdressing, they'll ask around to figure out what to wear (my guests are already asking what other guests are wearing, lol). I added something on my wedding website to let guests know the ceremony is outside (to give a hint hint) in case they want to reconsider heels or bring something to keep them warm. This is just for comfort though.

EDIT: I'm reading through the comments....are people recommending that "Suggested attire: semi-formal" is rude? I've seen this on just about every wedding website I've ever looked up....my whole life seems like a lie...

Just hope they ask!! I'm worried about this as well but as you can see there's no way around it. Maybe you can just bring it up in casual conversation? "Have you decided what you are going to wear?" Then maybe it'll start a dialogue.