There are multiple definitions:

1. direct feature statistics(English)

   • OFS
   • Statistics

2. disease free survival(English)

   • LRFS, LVI, MFS, NAC, OS, PNI, LODDS, TNM
   • Epidemiology, Prognosis
   • https://doi.org…000000000003468

3. decayed and filled surface(English)

   • CFA, COHIP-SF
   • Dentistry
   • https://doi.org…25.2012.00338.x

4. double-fortified salt(English)

   • may have a small positive impact on hemoglobin concentration and the prevalence of anemia compared to iodized salt
   • CBA, cRCT, EPOC, IS
   • Nutrition, Erythrocyte
   • https://doi.org…8.CD013463.pub2