@SKjames wrote:
.....Is this wording about "adding real value" actually listed anywhere official or is it just an unofficial litmus test used by many rental property owners?
No, that wording is not listed anywhere; it was simply coined by another member of this Community and is unofficial (as opposed to the following):
An expense is for an improvement if it results in a betterment to your property, restores your property, or adapts your property to a new or different use.
https://www.irs.gov/publications/p527#en_US_2020_publink1000219015
There is no requirement that an expense "add real value" to the property in order to be considered an "improvement". Although many (if not most) improvements do result in an increase in the value of the property to which they attach, there is no requirement that they do so.
