when member click on a link i want the link to open in new tap,i use html code but guest also can see it not my permission setting problem just for link in topic to open in new tap for member......

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The answer above is correct, but just in case you mean force all links in a post to open in a new tab, you can:

Go to ACP >> Display >> Templates >> General >> viewtopic_body

Post this at the end of the whole code:

Code:

<base target="_blank"/>

click "Save", and then press next to the viewtopic_body template. Hope this helped.