Let's go through the spotting rules one by one.
"A subtitle line preferably contains at most 37 characters, with a hard limit of 40 characters."
For a standard horizontal video, try 37 or 40 characters and set your hard limit to 40 or 43. If you're shooting vertical videos, we recommend going for 25 characters and a hard limit of 29 characters.
"A subtitle preferably contains at most 2 lines, with a hard limit of 3 lines".
We don't really recommend going much higher then 2 lines to ensure a good readability for your clients. Unless if you're shooting vertical videos, then you could set it to 3 lines with a hard limit of 4 lines.
"Keep the word rate below 180 words per minute."
Keeping the word rate below 180 words per minute ensures your audience will be comfortable reading the subtitles.
"When the gap between consecutive subtitles is less than 2 seconds, the first subtitle will be displayed such that the minimum distance to the next title is X seconds.
The X refers to the opening (in seconds) that we leave in between two subtitles. Usually, that gap is three frames, which corresponds to 0,12 seconds (seeing as one frame is 0,04 seconds in Europe).
We would highly recommend using this setting, as it makes for a comfortable reading experience for your audience.
"Snap the subtitle appearance timing to the shot change if it is closer than 0,5 seconds."
We perform shot detection on all videos. That means that with this setting, we put the subtitles on the shot change instead of right before or right after a shot change. This is done to make the subtitling visually appealing.
"Fade out for 0,5 seconds after the last spoken word in the subtitle."
Letting the subtitle stay on the screen 0,5 seconds longer after the last word has been spoken, gives your audience enough time to read the subtitle fully.
"A subtitle preferably is between 2 and 5 seconds.
This is the standard length of a subtitle.
"Prevent splitting these words from the next word"
This setting prevents you from making a subtitle line ending in "a / the / ...", so that your subtitle line doesn't read "he went out with the" but reads "he went out with the dog".