Standard format markers (SFM) are combinations of characters embedded into the text to indicate book, chapter, verse, etc. Standard format markers contain a backward slash (\) as the first character. Adapt It uses these markers in many ways, including for navigating through the text, filtering information, and importing and exporting text. In most cases, these markers are part of the source text inputted into Adapt It. See Source Text preparation. Adapt It uses the SFM automatically and generally you do not have to deal with them directly.
You can out more information about SFM in the documentation of translations tools such and Paratext, Toolbox, and Shoebox.