diff --git a/c/reg_test/expected/out b/c/reg_test/expected/out
index 27a48fa1c..821e6a774 100644
--- a/c/reg_test/expected/out
+++ b/c/reg_test/expected/out
@@ -14155,3 +14155,91 @@ x 0.676537984365847889
 a zee
 i 4
 
+
+================================================================
+JSON OUTPUT
+
+mlr --ojson cat ./reg_test/input/json-output-options.dkvp
+{ "a": 1, "b": "x", "c": 3 }
+{ "d": 4 }
+{ "e": 5, "f": 6 }
+
+mlr --ojson --jvtemp cat ./reg_test/input/json-output-options.dkvp
+{
+  "a": 1,
+  "b": "x",
+  "c": 3
+}
+{
+  "d": 4
+}
+{
+  "e": 5,
+  "f": 6
+}
+
+mlr --ojson --jotemp cat ./reg_test/input/json-output-options.dkvp
+[
+{ "a": 1, "b": "x", "c": 3 }
+,{ "d": 4 }
+,{ "e": 5, "f": 6 }
+]
+
+mlr --ojson --jvtemp --jotemp cat ./reg_test/input/json-output-options.dkvp
+[
+{
+  "a": 1,
+  "b": "x",
+  "c": 3
+}
+,{
+  "d": 4
+}
+,{
+  "e": 5,
+  "f": 6
+}
+]
+
+mlr --ojson --jqtemp cat ./reg_test/input/json-output-options.dkvp
+{ "a": "1", "b": "x", "c": "3" }
+{ "d": "4" }
+{ "e": "5", "f": "6" }
+
+mlr --ojson --jvtemp --jqtemp cat ./reg_test/input/json-output-options.dkvp
+{
+  "a": "1",
+  "b": "x",
+  "c": "3"
+}
+{
+  "d": "4"
+}
+{
+  "e": "5",
+  "f": "6"
+}
+
+mlr --ojson --jotemp --jqtemp cat ./reg_test/input/json-output-options.dkvp
+[
+{ "a": "1", "b": "x", "c": "3" }
+,{ "d": "4" }
+,{ "e": "5", "f": "6" }
+]
+
+mlr --ojson --jvtemp --jotemp --jqtemp cat ./reg_test/input/json-output-options.dkvp
+[
+{
+  "a": "1",
+  "b": "x",
+  "c": "3"
+}
+,{
+  "d": "4"
+}
+,{
+  "e": "5",
+  "f": "6"
+}
+]
+
diff --git a/c/reg_test/input/Makefile.am b/c/reg_test/input/Makefile.am
index e3ac6d9e7..8da90b900 100644
--- a/c/reg_test/input/Makefile.am
+++ b/c/reg_test/input/Makefile.am
@@ -69,6 +69,7 @@ EXTRA_DIST=	\
 		join-het.dkvp \
 		joina.dkvp \
 		joinb.dkvp \
+		json-output-options.dkvp \
 		logi.dkvp \
 		merge-fields-abxy.dkvp \
 		merge-fields-in-out.csv \
diff --git a/c/reg_test/input/json-output-options.dkvp b/c/reg_test/input/json-output-options.dkvp
new file mode 100644
index 000000000..e7679fe08
--- /dev/null
+++ b/c/reg_test/input/json-output-options.dkvp
@@ -0,0 +1,3 @@
+a=1,b=x,c=3
+d=4
+e=5,f=6
diff --git a/c/reg_test/run b/c/reg_test/run
index 69e09e814..75b1556b5 100755
--- a/c/reg_test/run
+++ b/c/reg_test/run
@@ -1441,6 +1441,18 @@ announce MULTI-CHARACTER IXS SPECIFIERS
 run_mlr --oxtab --idkvp --mmap  --irs lf   --ifs '\x2c'  --ips '\075'  cut -o -f x,a,i $indir/multi-sep.dkvp
 run_mlr --oxtab --idkvp --mmap  --irs lf   --ifs /, --ips '\x3d\x3a' cut -o -f x,a,i $indir/multi-sep.dkvp
 
+# ================================================================
+announce JSON OUTPUT
+
+run_mlr --ojson                            cat $indir/json-output-options.dkvp
+run_mlr --ojson --jvtemp                   cat $indir/json-output-options.dkvp
+run_mlr --ojson --jotemp                   cat $indir/json-output-options.dkvp
+run_mlr --ojson --jvtemp --jotemp          cat $indir/json-output-options.dkvp
+run_mlr --ojson                   --jqtemp cat $indir/json-output-options.dkvp
+run_mlr --ojson --jvtemp          --jqtemp cat $indir/json-output-options.dkvp
+run_mlr --ojson --jotemp          --jqtemp cat $indir/json-output-options.dkvp
+run_mlr --ojson --jvtemp --jotemp --jqtemp cat $indir/json-output-options.dkvp
+
 # ================================================================
 # A key feature of this regression script is that it can be invoked from any
 # directory. Depending on the directory it's invoked from, the path to $outdir
diff --git a/c/todo.txt b/c/todo.txt
index 54a15bd13..5d972a493 100644
--- a/c/todo.txt
+++ b/c/todo.txt
@@ -11,6 +11,7 @@ TOP OF LIST
 * json output x 2
 * tabular-json input
 * spec & impl for multilevel emit
+* bare-boolean with block
 
 ----------------------------------------------------------------
 * \0 example into mld:ref:regex
@@ -39,6 +40,7 @@ TOP OF LIST
 * JSON I/O:
   - input: https://github.com/udp/json-parser ? ; http://www.json.org/ C section
   - output: mlr-native json output is trivial & just do it.
+    ! turn the iffing into precomputed separtor strings
   - cover x 2
   - define 'tabular JSON' by example @ mld