Each time you make a donation you can choose if you want to share your contact info with the charity and/or let other users see who you donated to via the Giving Feed. Click this link to learn more about the Giving Feed.
If you want the donation to only appear on the Giving Feed, checkmark the box 'Include donation on the public Giving Feed.’ Note, the amount will not appear, just the organization you donated to:
If you only want to share your contact info with the charity, select the box 'Share name and email with charity’:
If you want both the charity and other users to know who you donated to, checkmark both boxes.
If you want the donation to be completely anonymous, do not checkmark either of the boxes.
If you want your donation to always appear on the Giving Feed without having to opt-in, go to your User Settings, and within the Sharing section, select ‘Automatically post donations to Giving Feed’