How to communicate "what to wear" for the wedding?

I would simply put something along the lines of traditional or similar indian attire is requested

Unless your guest list is pretty much all Indian, I wouldn't expect your guests to have traditional Indian wedding attire and it would be inconsiderate to make them purchase expensive attire just for one day.

I agree with Starlight. I wouldn't go out and spend a lot of money on an Indian outfit, just because it's your wedding (no offense, but it would just be money that I could use to use on bills instead of something I might wear once). On your invites and by word of mouth, make it clear that it's an Indian wedding. People will get that it will be appropriate to wear Indian wedding clothing. On your website you could also have a section that says to please feel free to wear Indian clothing but that it is not required. Black tie optional doesn't sound like the look you are going for at all.

I would phrase it as Traditional Indian wedding attire suggested" with an asterisk (*) at the bottom of invitation. I think "suggested" is more of~ if you have it wear it. "Requested" is asking

Your guests to purchase. Just my thoughts.

This could be difficult if your guests don't have clothing like you are looking for. I don't and I sure as heck wouldn't buy something just to wear to a wedding.

However if you have a website put it there, not on the invite. We are getting married in the woods and are having a casual wedding. However FHs family is far more formal. So I wrote: what to wear— we are planning a casual and laid back wedding. Our suggestion is to leave the balls gown, tie and suite at home , but to pack your dancing shoes and party pants (or shorts, it will be July aftet all) For women we strongly suggest flat shoes or flip flops as heels will sink in the ground. We are not the fashion police, so wear whatever makes you comfortable.

Maybe you could put, we encourage guests who already own traditional indian attire, to come dressed to impress or something along those lines, but make it clear that you are not expecting everyone to purchase a specific outfit. However, if you think 100‰ of guests would already own it, you could simply say that its suggested..

Adults can dress themselves - unless it is true Black Tie, you don't put anything. You could say "Please feel free to wear traditional Indian attire" on your website but nothing goes on the invitation. I would guess that your Indian guests will already wear it, and your non-Indian guests are not going to buy anything, so you really don't need to mention it at all.

I feel like Stephanie is onto something with her response.

If it were me, I'd put something like "Black Tie or Traditional Attire only, please."

But make sure if you say Black Tie you are truly having a black tie wedding - live band, multiple course, plated, served dinner, premium open bar, evening wedding (after 6 pm), very formal venue, etc. IF you arent, you can't ask say Black Tie just because you want people to dress nicely. Black tie involves full length gowns and tuxedos. If your guests rent $200 tuxedos for a non black-tie wedding they will be very angry.

For our wedding we did: Historical and Fantasy costuming encouraged

Agree that you can't ask someone to wear traditional indian garb, even if they are Indian

Note it on the website and hope for the best. But really you can't require that they wear it, only suggest.