Blocking

The official responds from Proboards:

You have the ability to block interactions from other members, using something called your Block List. When you add a member to your block list, you can limit interactions with them in the following ways:

Hide this member's posts: When viewing a thread that this member has posted in, you will not see their posts. Instead, you will see a button labeled "Display Post". If you click this button you can see what the blocked member posted.

Do not let this member start new conversations with me: The blocked member will not be able to start a new conversation with you. You cannot block conversations from staff members, however, and you'll still receive messages from any existing conversations with the blocked user until you leave the conversation via the Actions dropdown at the top of the conversation.

Do not let this member follow me or my activities: The member will not be able to follow you, view your activity list, or see your email address.

Block notifications from this member: You will not receive notifications related to actions that this member performs. For example, if the blocked member quotes you in a thread, you will not receive a notification about it, even if you have enabled notifications about quotes.