What is the short parameter group name for stable isotopes?

[jmusgs]

I have a working Shiny app that retrieves data by State and parameter group. I was recently asked to find data for N15 of NO3, and realized I wasn't getting stable isotopes. The app uses the short names for parameter groups: readNWISqw {dataRetrieval},

Details Valid parameter code groups are "All," or group codes: Code Description INF Information PHY Physical INM Inorganics, Major, Metals (major cations) INN Inorganics, Major, Non-metals (major anions) NUT Nutrient MBI Microbiological BIO Biological IMN Inorganics, Minor, Non-metals IMM Inorganics, Minor, Metals TOX Toxicity OPE Organics, pesticide OPC Organics, PCBs OOT Organics, other RAD Radiochemical SED Sediment POP Population/community

Although stable isotopes are not listed, they should be "ISO" based on the url such as: https://nwis.waterdata.usgs.gov/nwis/qwdata/?site_no=413144073115701&agency_cd=USGS&param_group=ISO&format=rdb, for example, for nutrients this same related url is: https://nwis.waterdata.usgs.gov/nwis/qwdata/?site_no=413144073115701&agency_cd=USGS&param_group=NUT&format=rdb.

I should be able to get to this with a construction in dataRetrieval like:

library(dataRetrieval)

test <- readNWISqw("413144073115701" , "NUT", startDate = "2000-01-01", endDate = "2010-12-31", expanded = TRUE, reshape = F, tz = "America/New_York") above example is for nutrients

[ldecicco-USGS]

It appears to be ISO. I'll add that and check to see if more have been added.