Private means "unlisted" basically, it won't show up anywhere, and will only be accessible to users who have the link.
The most common usage for them is probably forum giveaways, which are giveaways posted in a thread. Have a look around the forum, there are puzzles leading to private giveaways, or just posted in threads like this.
I would also recommend reading the FAQ and the Guidelines as they cover every question you could ever ask about Steamgifts.
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I am confused. You say you are new, but you have been active here for over 3 years.
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Use the reply link under a comment. If you do the user sees a notification.
I have no open invite only giveaways, but the can be in this form or like this http://www.steamgifts.com/giveaway/UsC3M/cities-xl-platinum or hidden in the html source code.
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What you need to do, to be invited to privet giveaway ? Im new guy and dont understand the system ?
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