There are multiple definitions:

1. phase shift keying(English)

   • digital modulation process that conveys data by modulating the phase of a constant frequency reference signal (the carrier wave)
   • CPM, GSM, MSK, TFM
   • Signal analysis, Data exchange
   • https://www.ope…ent-section-1.6

2. polysaccharide K(English)

   • UFT, LV, CRC
   • Oncology, Therapeutic approaches, Chemotherapy
   • https://doi.org…nticanres.16872