Guō Jīng 郭京
By traditional attribution, a Táng Sūzhōu sīhù cānjūn 蘇州司戶參軍 (revenue-section officer of Sūzhōu prefecture); by the consensus of SòngQīng evidential scholarship, a fictional or pseudonymous figure under whose name the Zhōuyì jǔzhèng 周易擧正 (KR1a0010) was composed in the late Five-Dynasties or early Northern Sòng. The Sìkù editors’ summary verdict in their tiyao on that work — “we suspect even the very name ‘Guō Jīng of the Táng’ stands between existence and non-existence” — captures the standard view.
The “Guō Jīng” of Zhōuyì jǔzhèng should not be confused with the late-Northern-Sòng (early-Jìn-conquest) Daoist-magical adept of the same name 郭京 active under Sòng Qīnzōng 欽宗 (1126), who is recorded in the Sòngshǐ and the Sōng zhīwén as the practitioner of the Liùjiǎ shénbīng 六甲神兵 ritual whose failure was implicated in the Jìn capture of Kāifēng — a different, securely historical figure with no connection to the Yì-textual world.