The colon's identifying a block of code.

冒号意味着一段代码的开始，这里的意思就是。

麻省理工公开课 - 计算机科学及编程导论课程节选

They could be used to make cheap radio-frequency identity tags in essence, printable bar-codes that transmit an identifying code in response to a pulsed radio signal.

ECONOMIST: Just press print

Eggs were packaged under the Country Eggs, Inc. brand name in 15 dozen bulk pack with the identifying plant code of P 1946 and P 1026.

CNN: STORY HIGHLIGHTS

Volunteer Lenore Snyder, however, said that she did not want to be identified and as a result did not provide her zip code and some other identifying characteristics in her profile.

FORBES: Harvard Professor Re-Identifies Anonymous Volunteers In DNA Study