dc5b5de8b09d0cd08c953805e29601860bbbd2ad
chmalee
  Mon Jul 27 11:44:51 2026 -0700
allow '>' one-way and '~' bidirectional relatedTracks entries, refs #37390

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

diff --git src/hg/makeDb/trackDb/relatedTracks.ra src/hg/makeDb/trackDb/relatedTracks.ra
index f3c59684c3f..fc3fb8350fa 100644
--- src/hg/makeDb/trackDb/relatedTracks.ra
+++ src/hg/makeDb/trackDb/relatedTracks.ra
@@ -1,17 +1,24 @@
-# A space delimited file of track relatedness. All entries must be reciprocal. Format:
+# A space delimited file of track relatedness. Format:
 # ucscDb track trackLinkingTo reason
+#
+# By default entries are reciprocal, so each relationship needs a line in each
+# direction. Prefix the first track with '>' for a relationship that only goes one
+# way, or with '~' to get both directions out of a single line when the reason is
+# the same either way. Neither form needs a reciprocal line. Format:
+# ucscDb >track trackLinkingTo reason
+# ucscDb ~track trackLinkingTo reason
 
 # hg38:
 hg38 knownGene knownGeneArchive View previous versions of GENCODE Genes
 hg38 knownGeneArchive knownGene View the latest GENCODE Genes version
 
 hg38 miRnaAtlas nonCodingRNAs View associated precursor miRnas
 hg38 nonCodingRNAs miRnaAtlas View expression of cleaved miRnas
 
 hg38 caddSuper gnomad View associated variants
 hg38 gnomad caddSuper View CADD scores for this variant and region
 
 hg38 constraintSuper gnomadPLI Predicted constraint metrics from gnomAD
 hg38 gnomadPLI constraintSuper Container track of various constraint scores
 
 hg38 gnomadStr strVar A collection of population-level STR variation tracks across the genome