Mishnah Berurah p art III on the halachahs of Shabbat with ” מוגה” [“proofread”] handwritten by the Chafetz Chaim. The gaon Chaim Zevulun Charlo”p’s s ignature is on the title page and the following leaf. [And on the last leaf of the Proclamation, signature: “Chaim Zevulun Harlap … son of the righteous Gaon Rabbi Yaakov Moshe Harlap shlita”].
The Chafetz Chaim would examine the books after they were brought to print, and indicate that the book is free of errors by writing “proofread.”
The gaon Rabbi Chaim Zevulun Charlo”p [1902-1966] was a disciple of Rabbi Avraham Yitzchak Kook and Rabbi Isser Zalman Meltzer, eventually rabbi of Rishon LeTziyon.