Update 10-functional-near-infrared-spectroscopy.md

src/04-modality-specific-files/10-functional-near-infrared-spectroscopy.md

@@ -177,7 +177,7 @@ Channels are a pairing of source and detector optodes with a specific light wave
 Unlike in other modalities, not all pairings of optodes correspond to meaningful data
 and not all pairs have to be recorded or represented in the data.  Note that the source
 and detector names used in the channel specifications are specified in the `*_optodes.tsv`
-file below.
+file below. The order of the required columns in the `*_channels.tsv` file MUST be listed as below.
 
 The BIDS specification supports several types of NIRS devices which output raw data in
 different forms. The type of measurement is specified in the type column. For example,