ACM handles directly visa support letters for ACM sponsored conferences.
The association does not issue formal invitation letters for visas. ACM can however issue a visa support letter. Those requesting a letter should allow up to one week to receive it, as requests are handled in the order they are received.
For visa support letters, please send all requests to firstname.lastname@example.org with the following information.
Name (as it appears on your passport) and mailing address
The name of the conference you wish to attend
Include your registration confirmation number
If you are the author of any papers accepted for the conference, please provide the title. If you are a speaker, please provide the title/topic of your speech.
Include a fax number or email address of where ACM can send the letter