YSK: Envelopes often have a postal barcode printed on them that contains your address, and you should censor that barcode if you're posting a picture of an envelope.
from /r/YouShouldKnow
YSK：信封上往往印有郵政條碼，裏面有你的地址，如果你要發一張信封的照片，你應該對這個條碼進行審查。
YSK：信封上往往印有郵政條碼，裏面有你的地址，如果你要發一張信封的照片，你應該對這個條碼進行審查。
YSK: Envelopes often have a postal barcode printed on them that contains your address, and you should censor that barcode if you're posting a picture of an envelope.
from /r/YouShouldKnow