Sentence:  In a thread called “Calm Before the Storm”, and in subsequent posts, Q established his legend as a government insider with top security <WSD>clearance</WSD> who knew the truth about a secret struggle for power involving Donald Trump, the “deep state”, Robert Mueller, the Clintons, pedophile rings, and other stuff. 
Meaning of the word marked with <WSD> tags:  A permission to have access to sensitive or secret documents or other information.