diff --git a/howto/postgresql.md b/howto/postgresql.md
index 8b875f5d8eb46fdb1e1f52680d92c6856cdc3ea0..c9d59cc351d0fedd51bfb9774e4c30340832d35e 100644
--- a/howto/postgresql.md
+++ b/howto/postgresql.md
@@ -1838,6 +1838,11 @@ encountered such errors so far.
 
 ### Backups misconfigurations
 
+<!-- note that this section is cross-referenced from the -->
+<!-- PgBackRestStanzaError, PgBackRestRepositoryError and -->
+<!-- PgBackRestExporterFailure alerts in prometheus-alerts.git change the -->
+<!-- link target there if you change the heading here. -->
+
 A certain number of conditions can be raised by the [backups
 monitoring system](#backups-monitoring) that will raise an alert. Those are, at the time
 of writing:
@@ -1861,6 +1866,10 @@ In all case, another idea is to [check backup health](#checking-backup-health).
 confirm (or not) that stanzas are properly configured, and outline
 misconfigured stanza or errors in the global repository configuration.
 
+The status code 99 means "other". This generally means that some external reason
+is causing things to not run correctly. For example permission errors that make
+the exporter unable to read from the backup directories.
+
 ### Disk is full or nearly full
 
 It's possible that pgBackRest backups are taking up all disk space on
@@ -2797,6 +2806,13 @@ See also:
 
 -->
 
+Technical debt that needs to eventually be addressed:
+
+* the `pgbackrest_exporter` currently runs as root since it needs to be able to
+  read from backup directories under all of the backup users. We want to
+  implement a better method for the exporter to get access to the files without
+  running as root.
+
 ## Goals
 
 <!-- include bugs to be fixed -->