In my JLPT workbook, I have the sentence:
就職活動で携帯電話を重用する学生が増えている。OB, OG訪問で約束を取り付けたり、採用担当者から面接日の連絡を受けたりするのも、常に持ち歩いている携帯の方が確実とみられているからだ。
I'm not sure what OB, OG訪問 means.
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Sign up to join this community"OB" and "OG" mean "Old boy" and "Old girl" respectively. "Old boy/girl" means an alumnus of something, or a previous member -- usually in reference to a school or club.
So for this example, it says "By meeting with an OB/OG, they arrange an appointment...". Although I'm not sure if the OB/OG here is one from their school (who has already gone through 就職活動 themselves) or of the company they are applying to, though the former seems to make more sense.
OB (オービー): "old boy", a male graduate of a school, alumnus, alumni
OG (オージー): "old girl", a female graduate of a school, alumnus, alumni