Well, it can be used in a story when creating a sense of mystery or code. Suppose the story has a secret message or a hidden language. 'Dot' as a short for 'o' can be part of that code. For example, if there is a map in the story with coded words, words with 'o' could be written with 'dot' instead to make it seem more cryptic. Also, in a story about a different dimension or parallel universe where language is distorted, 'dot' for 'o' can be a natural part of that world's language.
In a story that involves a lot of written communication like letters or notes within the plot, 'dot' can be used as 'o'. Let's say a character is writing a diary entry but is trying to be secretive or is in a situation where they can't write fully. They might use 'dot' for 'o' to disguise their writing. Also, in a story about a new form of art that combines language and visual elements, 'dot' for 'o' can be used to create unique visual and written patterns.
One way is in the naming of characters or places. For example, if there is a character named 'Spot' but the author wants to play with the name, they could write it as 'S.dot' in the story. Another way could be in the dialogue where a character who is in a hurry or has a unique speaking style might say 'dot' instead of 'o' in words.