Concerning meaning

He reiterated his concern for the utmost confi­dentiality concerning the location.

Arguments concerning contact with tip lines became heated as well.

When Dean questioned her, she told of receiving a phone call concerning that same property some weeks earlier.

In September 1844 Calhoun, then secretary of state, sent Green to Texas ostensibly as consul at Galveston, but actually, it appears, to report to the administration, then considering the question of the annexation of Texas, concerning the political situation in Texas and Mexico.

I do remember some theories concerning relativity suggesting some sort of motion in space might allow time travel if space-time geometrics are possible.