diff --git a/c/reg_test/input/Makefile.am b/c/reg_test/input/Makefile.am
index 7c152fe3b..70eb2d0bf 100644
--- a/c/reg_test/input/Makefile.am
+++ b/c/reg_test/input/Makefile.am
@@ -78,6 +78,12 @@ EXTRA_DIST=	\
 		missings.dkvp \
 		mixed-types.xtab \
 		modarith.dat \
+		multi-format-join-a.csv \
+		multi-format-join-a.dkvp \
+		multi-format-join-a.json \
+		multi-format-join-b.csv \
+		multi-format-join-b.dkvp \
+		multi-format-join-b.json \
 		multi-ips.dkvp \
 		multi-sep.csv \
 		multi-sep.dkvp \
diff --git a/c/reg_test/input/multi-format-join-a.csv b/c/reg_test/input/multi-format-join-a.csv
new file mode 100644
index 000000000..7d79690b4
--- /dev/null
+++ b/c/reg_test/input/multi-format-join-a.csv
@@ -0,0 +1,5 @@
+x,a
+1,2
+2,3
+3,4
+4,5
diff --git a/c/reg_test/input/multi-format-join-a.dkvp b/c/reg_test/input/multi-format-join-a.dkvp
new file mode 100644
index 000000000..f0e325c99
--- /dev/null
+++ b/c/reg_test/input/multi-format-join-a.dkvp
@@ -0,0 +1,4 @@
+x=1,a=2
+x=2,a=3
+x=3,a=4
+x=4,a=5
diff --git a/c/reg_test/input/multi-format-join-a.json b/c/reg_test/input/multi-format-join-a.json
new file mode 100644
index 000000000..1870d491a
--- /dev/null
+++ b/c/reg_test/input/multi-format-join-a.json
@@ -0,0 +1,4 @@
+{"x":1,"a":2}
+{"x":2,"a":3}
+{"x":3,"a":4}
+{"x":4,"a":5}
diff --git a/c/reg_test/input/multi-format-join-b.csv b/c/reg_test/input/multi-format-join-b.csv
new file mode 100644
index 000000000..02686bbaa
--- /dev/null
+++ b/c/reg_test/input/multi-format-join-b.csv
@@ -0,0 +1,5 @@
+x,b
+1,20
+2,30
+3,40
+4,50
diff --git a/c/reg_test/input/multi-format-join-b.dkvp b/c/reg_test/input/multi-format-join-b.dkvp
new file mode 100644
index 000000000..b366c94a3
--- /dev/null
+++ b/c/reg_test/input/multi-format-join-b.dkvp
@@ -0,0 +1,4 @@
+x=1,b=20
+x=2,b=30
+x=3,b=40
+x=4,b=50
diff --git a/c/reg_test/input/multi-format-join-b.json b/c/reg_test/input/multi-format-join-b.json
new file mode 100644
index 000000000..de1314630
--- /dev/null
+++ b/c/reg_test/input/multi-format-join-b.json
@@ -0,0 +1,4 @@
+{"x":1,"b":20}
+{"x":2,"b":30}
+{"x":3,"b":40}
+{"x":4,"b":50}
diff --git a/c/todo.txt b/c/todo.txt
index 73ec7511d..2098ab9e5 100644
--- a/c/todo.txt
+++ b/c/todo.txt
@@ -1,69 +1,25 @@
 ================================================================
 BUGFIXES
 
-:D
-
-cat a.d
-x=1,a=2
-x=2,a=3
-x=3,a=4
-x=4,a=5
-
-cat b.d
-x=1,b=20
-x=2,b=30
-x=3,b=40
-x=4,b=50
-
-$ mlr join -j x -f a.d b.d
-x=1,a=2,b=20
-x=2,a=3,b=30
-x=3,a=4,b=40
-x=4,a=5,b=50
-
-$ mlr --csvlite join -j x -f a.c b.c
-x,a,b
-1,2,20
-2,3,30
-3,4,40
-4,5,50
-
-$ mlr --json join -j x -f a.j b.j
-{ "x": 2, "a": 3, "b": 30 }
-{ "x": 3, "a": 4, "b": 40 }
-{ "x": 4, "a": 5, "b": 50 }
-
-(lldb) run --icsvlite --ocsvlite join -u --ur -i dkvp     -j x -f a.d b.v
-Process 993 stopped
-* thread #1: tid = 0x2a760b, 0x0000000100042be9 mlrg`merge_options(popts=0x0000000100103370) + 89 at mapper_join.c:488, queue = 'com.apple.main-thread', stop reason = step over
-    frame #0: 0x0000000100042be9 mlrg`merge_options(popts=0x0000000100103370) + 89 at mapper_join.c:488
-   485      popts->input_file_format = MLR_GLOBALS.popts->ifile_fmt;
-   486    if (popts->irs               == NULL)
-   487      popts->irs = MLR_GLOBALS.popts->irs;
--> 488    if (popts->ifs               == NULL)
-   489      popts->ifs = MLR_GLOBALS.popts->ifs;
-   490    if (popts->ips               == NULL)
-   491      popts->ips = MLR_GLOBALS.popts->ips;
+mlr --icsvlite --ocsvlite join -u --ur -i dkvp -j x -f a.d b.v
 (lldb) p MLR_GLOBALS.popts->ips
 (char *) $21 = 0x000000010005c5b9 "(N/A)"
 
 ================================================================
 TOP-OF-LIST SUMMARY
 
-* JSON input: UT/doc items
-* doc items
+* multi-format join: fix default ixses
 * doc section on programmability spectrum (perl to asic) & how much effort is/isn't worth putting into miller. & maybe shouldabeen pickalanguage w/ I/O support and API.
 * in why-miller: list the intersection points. perf; multifmt; math+strings; expressive/programmable; compact notation; pipe-friendly.
 * dev page re releases, valgrinds, distros, etc
-
-! rh/fedora/centos mlr-3.3.2: after patch-file for manpage
-? make a 3.4.0 w/ all but oosvar/begin-end/pattern-action? what to do about filter/gate which is transitional?
-  -> or maybe ok: due to semantic versioning i can break gate in a 4.0.0 with a clear conscience. mk clear @ dox.
-
-* explode & any other komosas/wolens from feature-request task.
 * valgrinds
 * xxxes
 
+! rh/fedora/centos mlr-3.3.2: after patch-file for manpage
+? make a 3.4.0 w/ all but oosvar/begin-end/pattern-action (gate is transitional)
+
+* explode & any other komosas/wolens from feature-request task.
+
 * parameterized emit: needs spec & impl
 * pattern-action: note that breaks the simple LHS/RHS partition I've enjoyed up until now
 
@@ -90,9 +46,6 @@ TOP-OF-LIST SUMMARY
 ----------------------------------------------------------------
 TOP-OF-LIST DETAILS
 
-* JSON I/O:
-  - UT: JSON/join. both/left/right json cases.
-
 * multilevel emit: spec & impl
 
 * pattern-action (bare-boolean with block) still experimental. if-else down the road perhaps ...
diff --git a/doc/mlr.1 b/doc/mlr.1
index acfe52279..72bfd15cc 100644
--- a/doc/mlr.1
+++ b/doc/mlr.1
@@ -2,12 +2,12 @@
 .\"     Title: mlr
 .\"    Author: [see the "AUTHOR" section]
 .\" Generator: ./mkman.rb
-.\"      Date: 2016-02-13
+.\"      Date: 2016-02-14
 .\"    Manual: \ \&
 .\"    Source: \ \&
 .\"  Language: English
 .\"
-.TH "MILLER" "1" "2016-02-13" "\ \&" "\ \&"
+.TH "MILLER" "1" "2016-02-14" "\ \&" "\ \&"
 .\" -----------------------------------------------------------------
 .\" * Portability definitions
 .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~