However, you could use:
* Rel. (This is common in academic writing)
* R/ship (This is less formal and more informal)
* R'ship (Similar to the above, but with an apostrophe)
It's important to note that using abbreviations for "relationship" might not be appropriate in all contexts. For example, using them in formal documents or business communication could be considered unprofessional.
Always consider your audience and the context when deciding whether to use an abbreviation.