clarify this FIXME

gridded_glm/libexec/_minute_gridder.py

@@ -161,7 +161,7 @@ def get_outpath_base(args):
     ops_environment, algorithm, platform, start_time, end_time, created_time = parse_glm_filename(args.filenames[0])
 
     sector_short = get_sector_shortstring(args)
-    mode = "M3" # FIXME: we're not always in M3
+    mode = "M3" # FIXME: is GLM always in M3?
 
     # example string: OR_GLM-L2-GLMC-M3_G17_s20182750032000_e20182750033000_c20210431923130.nc
     dsname = "{environment_prefix}_GLM-L2-GLM{sector_short}-{mode}_{platform}_s{start_time}_e{end_time}_c{created_time}.nc".format(