Understanding the Subtitling Area

A – Subtitle number.
B – Timecode indicating the beginning of the subtitle (HH:MM:SS:FF).
C – Total duration of the subtitle.
D – Timecode indicating the end of the subtitle.
E – Number of characters on the first / second line (spaces included).
F – Total number of characters on both lines (including space between them).
G – Line indicating whether the subtitle complies with the reading speed. The line is green as the subtitle does not surpass the maximum 17 cps in this example (it is 16.3 cps). If it did, it'll be red.
H – Subtitle reading speed (16.3 cps) and number of characters written (49) of a maximum of 51.

Note that each subtitle box has a designated field for annotations and remarks.
Remarks are internal notes for the next person working on the file/project.
Annotations are mainly used in Master Template creation to help translators understand slang and wordplay.