General:
* WF: This is a straightforward abbreviation that is commonly used.
* Freq: This is a shorter abbreviation that can be used when space is limited.
Specific contexts:
* TF-IDF: This stands for "Term Frequency-Inverse Document Frequency" and is used in information retrieval and natural language processing.
* Zipf's Law: This refers to the observation that the frequency of a word is inversely proportional to its rank in the frequency table.
The best abbreviation to use will depend on the specific situation.