diff --git a/subr/build_args.subr b/subr/build_args.subr
index 38f10c5..2175665 100644
--- a/subr/build_args.subr
+++ b/subr/build_args.subr
@@ -1,3 +1,7 @@
+#
+# set -o noglob is assumed.
+#
+
 BUILD_ARGS_SPEC="
 	ARG_IPV4_ONLY:-4
 	ARG_IPV6_ONLY:-6
diff --git a/subr/build_checks.subr b/subr/build_checks.subr
index 08abc68..055ed87 100644
--- a/subr/build_checks.subr
+++ b/subr/build_checks.subr
@@ -1,3 +1,7 @@
+#
+# set -o noglob is assumed.
+#
+
 build_checks() {
 	local __ _exit _pname;
 	for __ in ${DEFAULT_CHECK_PATH_VARS}; do
diff --git a/subr/ex_pkg_dispatch.subr b/subr/ex_pkg_dispatch.subr
index ad41616..7a8a95d 100644
--- a/subr/ex_pkg_dispatch.subr
+++ b/subr/ex_pkg_dispatch.subr
@@ -1,5 +1,9 @@
 #
-# set -o errexit -o noglob are assumed.
+# set -o noglob is assumed.
+# WARNING: ex_pkg_dispatch(), its caller, and its callers must _NOT_ be executed
+# as part of conditional evaluation, e.g. if, until, while, !, or && and ||, as
+# doing so would inhibit set -o errexit during execution of this function and its
+# subshell(!).  Instead, call ex_pkg_dispatch() and subsequently evaluate ${?}.
 #
 
 ex_pkg_dispatch() {
diff --git a/subr/ex_rtl.subr b/subr/ex_rtl.subr
index ecca3c8..d37e708 100644
--- a/subr/ex_rtl.subr
+++ b/subr/ex_rtl.subr
@@ -1,5 +1,5 @@
 #
-# set -o errexit -o noglob are assumed.
+# set -o noglob is assumed.
 #
 
 EXP_RTL_IFS="${IFS}";
diff --git a/subr/ex_rtl_fetch.subr b/subr/ex_rtl_fetch.subr
index c5dfc55..5e76e42 100644
--- a/subr/ex_rtl_fetch.subr
+++ b/subr/ex_rtl_fetch.subr
@@ -1,5 +1,5 @@
 #
-# set -o errexit -o noglob are assumed.
+# set -o noglob is assumed.
 #
 
 exp_rtl_fetch_url_git() {
diff --git a/subr/ex_rtl_fileop.subr b/subr/ex_rtl_fileop.subr
index 0666e7d..6245783 100644
--- a/subr/ex_rtl_fileop.subr
+++ b/subr/ex_rtl_fileop.subr
@@ -1,5 +1,5 @@
 #
-# set -o errexit -o noglob are assumed.
+# set -o noglob is assumed.
 #
 
 exp_rtl_fileop_check() {
diff --git a/subr/ex_rtl_install.subr b/subr/ex_rtl_install.subr
index 5dc2a08..19504a8 100644
--- a/subr/ex_rtl_install.subr
+++ b/subr/ex_rtl_install.subr
@@ -1,5 +1,5 @@
 #
-# set -o errexit -o noglob are assumed.
+# set -o noglob is assumed.
 #
 
 ex_rtl_install() {
diff --git a/subr/ex_rtl_log.subr b/subr/ex_rtl_log.subr
index 71e52fa..43e22ec 100644
--- a/subr/ex_rtl_log.subr
+++ b/subr/ex_rtl_log.subr
@@ -1,5 +1,5 @@
 #
-# set -o errexit -o noglob are assumed.
+# set -o noglob is assumed.
 #
 
 ex_rtl_log_env_vars() {
diff --git a/subr/ex_rtl_state.subr b/subr/ex_rtl_state.subr
index fa07ff3..1cdd42a 100644
--- a/subr/ex_rtl_state.subr
+++ b/subr/ex_rtl_state.subr
@@ -1,5 +1,5 @@
 #
-# set -o errexit -o noglob are assumed.
+# set -o noglob is assumed.
 #
 
 ex_rtl_state_set() {