What is the format of bug's description in the duplicate dataset?

For the duplicate dataset, i hvae noticed there are many flags in the description of bug, such as ";;",";;;;","\tat", etc. Even though, there are some flag ";" in middle of one sentence, so i want to know what's the menas of these flags?

[SabaRG]

These are usually used in source codes, e.g., ";" is used for the end of a statement in C++ language. The "\t" is used to indicate a Tab character in C++, and "\tat" is kind of equal to " at". These are not related to the dataset. You should be familiar with those applications related to bug reports.