diff --git a/README.md b/README.md
index 2c23a1495..31ce577cc 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ positionally-indexed data as a special case.)
 
 Features:
 
-* I/O formats including **tabular pretty-printing**
+* I/O formats including **tabular pretty-printing** and **positionally indexed** (Unix-toolkit style)
 
 * **Conversion** between formats
 
diff --git a/c/todo.txt b/c/todo.txt
index 3fc8c5cd8..675bf906c 100644
--- a/c/todo.txt
+++ b/c/todo.txt
@@ -11,21 +11,6 @@ MINOR:
 
 * double-check for off-by-one buflen in cline/sline
 
-* define dkvp, nidx, etc @ cover x 2
-
-* cover:
-  ### mlr --csv cut -f hostname,uptime mydata.csv
-  ### mlr filter '$status != "down" && $upsec >= 10000' *.csv
-  ### mlr --nidx put '$sum = $7 + 2.1*$8' *.dat
-  ### grep -v '^#' /etc/group | mlr --ifs : --nidx --opprint label group,pass,gid,member then sort -f group
-  ### mlr join -j account_id -f accounts.dat then group-by account_name balances.dat
-  ### mlr stats1 -a min,mean,max,p10,p50,p90 -f flag,u,v data/*
-  ### mlr stats2 -a linreg-pca -f u,v -g shape data/*
-
-  --> long names --group x all??
-
-* build page doesn't belong in developer info -- this is user info
-
 * scroll-stalls in mlrdoc!! really bad on the droid.
 
 ----------------------------------------------------------------
diff --git a/doc/content-for-index.html b/doc/content-for-index.html
index 58ac9eb55..32b18a582 100644
--- a/doc/content-for-index.html
+++ b/doc/content-for-index.html
@@ -20,7 +20,7 @@ positionally-indexed data as a special case.)
 <p/> Features:
 <ul>
 
-<li> I/O formats including <b>tabular pretty-printing</b>
+<li> I/O formats including <b>tabular pretty-printing</b> and <b>positionally indexed</b> (Unix-toolkit style)
 <li> <b>Conversion</b> between formats
 <li> <b>Format-aware processing</b>: e.g. CSV sort and tac keep header lines first
 <li> High-throughput <b>performance</b> on par with the Unix toolkit
diff --git a/doc/data-examples.html b/doc/data-examples.html
index bcd636fac..8da9db109 100644
--- a/doc/data-examples.html
+++ b/doc/data-examples.html
@@ -218,281 +218,4 @@ CITRUS COUNTY       1332.900000            79974.900000           483785.100000
 <p/>
 <div class="pokipanel">
 <pre>
-$ cat data/flins.csv | mlr --icsv --oxtab stats2 -a corr,linreg-ols,r2 -f tiv_2011,tiv_2012
-tiv_2011_tiv_2012_corr  0.973050
-tiv_2011_tiv_2012_ols_m 0.983558
-tiv_2011_tiv_2012_ols_b 433854.642897
-tiv_2011_tiv_2012_ols_n 36634
-tiv_2011_tiv_2012_r2    0.946826
-</pre>
-</div>
-<p/>
-<p/>
-<div class="pokipanel">
-<pre>
-$ cat data/flins.csv | mlr --icsv --opprint stats2 -a corr,linreg-ols,r2 -f tiv_2011,tiv_2012 -g county
-county              tiv_2011_tiv_2012_corr tiv_2011_tiv_2012_ols_m tiv_2011_tiv_2012_ols_b tiv_2011_tiv_2012_ols_n tiv_2011_tiv_2012_r2
-CLAY COUNTY         0.962716               1.090115                46450.531268            363                     0.926822
-SUWANNEE COUNTY     0.989208               1.074658                36253.003174            154                     0.978533
-NASSAU COUNTY       0.973135               1.296321                -45369.242673           135                     0.946993
-COLUMBIA COUNTY     0.999492               0.931447                117183.548383           125                     0.998985
-ST  JOHNS COUNTY    0.966170               1.230056                -596.623856             657                     0.933485
-BAKER COUNTY        0.963515               0.942771                29063.065747            70                      0.928360
-BRADFORD COUNTY     0.999766               0.849029                69544.341944            31                      0.999533
-HAMILTON COUNTY     0.987026               1.224952                1045.052170             35                      0.974220
-UNION COUNTY        0.997745               1.432575                -56.125738              15                      0.995495
-MADISON COUNTY      0.985213               1.512114                -84278.028498           81                      0.970645
-LAFAYETTE COUNTY    0.967499               1.134289                9904.860798             68                      0.936055
-FLAGLER COUNTY      0.984854               1.007922                95340.508354            204                     0.969937
-DUVAL COUNTY        0.978815               1.245630                -60831.675023           1894                    0.958079
-LAKE COUNTY         0.999727               1.293864                -107695.848518          206                     0.999455
-VOLUSIA COUNTY      0.994636               1.202247                -36277.755477           1367                    0.989300
-PUTNAM COUNTY       0.961167               1.176294                6405.060826             268                     0.923841
-MARION COUNTY       0.975774               1.175642                20434.945602            1138                    0.952136
-SUMTER COUNTY       0.989760               1.372395                -62648.989750           158                     0.979625
-LEON COUNTY         0.978644               1.259681                -90816.033261           246                     0.957743
-FRANKLIN COUNTY     0.989430               1.048513                36026.508852            37                      0.978972
-LIBERTY COUNTY      0.995175               1.369834                -79755.544362           36                      0.990373
-GADSDEN COUNTY      0.997898               1.180585                7335.013009             196                     0.995801
-WAKULLA COUNTY      0.978267               1.192350                44607.922080            85                      0.957006
-JEFFERSON COUNTY    0.976543               0.976066                74884.170791            57                      0.953637
-TAYLOR COUNTY       0.981770               1.386188                -56856.945239           113                     0.963873
-BAY COUNTY          0.975404               1.004452                373000.300167           403                     0.951412
-WALTON COUNTY       0.985855               1.319583                -83273.091503           288                     0.971909
-JACKSON COUNTY      0.991195               1.171538                8128.438198             208                     0.982468
-CALHOUN COUNTY      0.967974               1.274077                -739.602262             68                      0.936973
-HOLMES COUNTY       0.997366               1.159384                42610.647058            40                      0.994738
-WASHINGTON COUNTY   0.982582               1.213413                -13125.214494           116                     0.965468
-GULF COUNTY         0.990367               1.135626                26094.474571            72                      0.980826
-ESCAMBIA COUNTY     0.986666               1.195336                46106.277408            494                     0.973509
-SANTA ROSA COUNTY   0.972696               1.013849                30496.045069            856                     0.946138
-OKALOOSA COUNTY     0.970781               1.462083                -116127.032201          1115                    0.942416
-ALACHUA COUNTY      0.982825               1.142748                52671.269211            973                     0.965945
-GILCHRIST COUNTY    0.977467               1.375740                -15309.425813           39                      0.955442
-LEVY COUNTY         0.956302               1.200506                265.391211              126                     0.914513
-DIXIE COUNTY        0.995780               1.640150                -98273.767115           40                      0.991578
-SEMINOLE COUNTY     0.985925               0.880108                427892.123991           1100                    0.972048
-ORANGE COUNTY       0.990658               0.872027                1298970.668186          1811                    0.981403
-BREVARD COUNTY      0.978015               1.271225                -19295.177646           872                     0.956513
-INDIAN RIVER COUNTY 0.985673               1.284620                -116579.613922          380                     0.971550
-MIAMI DADE COUNTY   0.987833               1.293106                -237168.505282          4315                    0.975815
-BROWARD COUNTY      0.983847               1.187689                81931.896276            3193                    0.967954
-MONROE COUNTY       0.982555               1.013142                455469.576218           152                     0.965414
-PALM BEACH COUNTY   0.982591               1.247594                -77252.429421           2791                    0.965485
-MARTIN COUNTY       0.975896               1.032873                8668.746202             109                     0.952374
-HENDRY COUNTY       0.971645               0.969699                208613.031856           74                      0.944093
-PASCO COUNTY        0.986556               1.288225                -152936.104164          790                     0.973294
-GLADES COUNTY       0.983518               0.982993                125666.627729           22                      0.967308
-HILLSBOROUGH COUNTY 0.985446               1.211620                214512.927989           1166                    0.971103
-HERNANDO COUNTY     0.974068               0.759748                701096.129434           120                     0.948809
-PINELLAS COUNTY     0.987215               1.154797                38609.763660            1774                    0.974593
-POLK COUNTY         0.979963               1.094848                153371.308143           1629                    0.960327
-North Fort Myers    -                      nan                     nan                     1                       -
-Orlando             -                      nan                     nan                     1                       -
-HIGHLANDS COUNTY    0.993054               1.528760                -300198.361569          369                     0.986157
-HARDEE COUNTY       0.977999               1.323440                -98513.434797           81                      0.956482
-MANATEE COUNTY      0.967526               1.068496                137190.708238           518                     0.936106
-OSCEOLA COUNTY      -                      nan                     nan                     1                       -
-LEE COUNTY          0.978945               1.252722                -16843.109269           678                     0.958334
-CHARLOTTE COUNTY    0.979024               1.013211                178461.328878           414                     0.958488
-COLLIER COUNTY      0.958031               1.169759                110270.385201           787                     0.917824
-SARASOTA COUNTY     0.984781               1.292514                -109939.723017          417                     0.969793
-DESOTO COUNTY       0.980130               1.286205                -9987.042982            108                     0.960654
-CITRUS COUNTY       0.989943               0.965940                138635.818880           384                     0.979986
-</pre>
-</div>
-<p/>
-
-<a id="Color/shape_data"/><h1>Color/shape data</h1>
-
-<p/> The <a href="data/colored-shapes.dkvp">colored-shapes.dkvp</a> file is some sample data produced by the
-<a href="https://github.com/johnkerl/miller/blob/master/doc/datagen/mkdat2">mkdat2</a> script. The idea is
-<ul>
-<li> Produce some data with known distributions and correlations, and verify that Miller recovers those properties empirically.
-<li> Each record is labeled with one of a few colors and one of a few shapes.
-<li> The <tt>flag</tt> field is 0 or 1, with probability dependent on color
-<li> The <tt>u</tt> field is plain uniform on the unit interval.
-<li> The <tt>v</tt> field is the same, except tightly correlated with <tt>u</tt> for red circles.
-<li> The <tt>w</tt> field is autocorrelated for each color/shape pair.
-<li> The <tt>x</tt> field is boring Gaussian with mean 5 and standard deviation about 1.2, with no dependence on color or shape.
-</ul>
-
-<p/> Peek at the data:
-<p/>
-<div class="pokipanel">
-<pre>
-$ wc -l data/colored-shapes.dkvp
-   10078 data/colored-shapes.dkvp
-</pre>
-</div>
-<p/>
-<p/>
-<div class="pokipanel">
-<pre>
-$ head -n 6 data/colored-shapes.dkvp | mlr --opprint cat
-color  shape    flag i  u                   v                    w                   x
-yellow triangle 1    11 0.6321695890307647  0.9887207810889004   0.4364983936735774  5.7981881667050565
-red    square   1    15 0.21966833570651523 0.001257332190235938 0.7927778364718627  2.944117399716207
-red    circle   1    16 0.20901671281497636 0.29005231936593445  0.13810280912907674 5.065034003400998
-red    square   0    48 0.9562743938458542  0.7467203085342884   0.7755423050923582  7.117831369597269
-purple triangle 0    51 0.4355354501763202  0.8591292672156728   0.8122903963006748  5.753094629505863
-red    square   0    64 0.2015510269821953  0.9531098083420033   0.7719912015786777  5.612050466474166
-</pre>
-</div>
-<p/>
-
-<p/> Look at uncategorized stats (using <a href="https://github.com/johnkerl/scripts/blob/master/fundam/creach"><tt>creach</tt></a> for spacing).
-Here it looks reasonable that <tt>u</tt> is unit-uniform; something&rsquo;s up with <tt>v</tt> but we can't yet see what:
-<p/>
-<div class="pokipanel">
-<pre>
-$ mlr --oxtab stats1 -a min,mean,max -f flag,u,v data/colored-shapes.dkvp | creach 3
-flag_min  0.000000
-flag_mean 0.398889
-flag_max  1.000000
-
-u_min     0.000044
-u_mean    0.498326
-u_max     0.999969
-
-v_min     -0.092709
-v_mean    0.497787
-v_max     1.072500
-</pre>
-</div>
-<p/>
-<p/>The histogram shows the different distribution of 0/1 flags:
-<p/>
-<div class="pokipanel">
-<pre>
-$ mlr --opprint histogram -f flag,u,v --lo -0.1 --hi 1.1 --nbins 12 data/colored-shapes.dkvp
-bin_lo    bin_hi   flag_count u_count v_count
--0.100000 0.000000 6058       0       36
-0.000000  0.100000 0          1062    988
-0.100000  0.200000 0          985     1003
-0.200000  0.300000 0          1024    1014
-0.300000  0.400000 0          1002    991
-0.400000  0.500000 0          989     1041
-0.500000  0.600000 0          1001    1016
-0.600000  0.700000 0          972     962
-0.700000  0.800000 0          1035    1070
-0.800000  0.900000 0          995     993
-0.900000  1.000000 4020       1013    939
-1.000000  1.100000 0          0       25
-</pre>
-</div>
-<p/>
-
-<p/> Look at univariate stats by color and shape. In particular,
-color-dependent flag probabilities pop out, aligning with their original
-Bernoulli probablities from the data-generator script:
-
-<p/>
-<div class="pokipanel">
-<pre>
-$ mlr --opprint stats1 -a min,mean,max -f flag,u,v -g color then sort -f color data/colored-shapes.dkvp
-color  flag_min flag_mean flag_max u_min    u_mean   u_max    v_min     v_mean   v_max
-blue   0.000000 0.584354  1.000000 0.000044 0.517717 0.999969 0.001489  0.491056 0.999576
-green  0.000000 0.209197  1.000000 0.000488 0.504861 0.999936 0.000501  0.499085 0.999676
-orange 0.000000 0.521452  1.000000 0.001235 0.490532 0.998885 0.002449  0.487764 0.998475
-purple 0.000000 0.090193  1.000000 0.000266 0.494005 0.999647 0.000364  0.497051 0.999975
-red    0.000000 0.303167  1.000000 0.000671 0.492560 0.999882 -0.092709 0.496535 1.072500
-yellow 0.000000 0.892427  1.000000 0.001300 0.497129 0.999923 0.000711  0.510627 0.999919
-</pre>
-</div>
-<p/>
-<p/>
-<div class="pokipanel">
-<pre>
-$ mlr --opprint stats1 -a min,mean,max -f flag,u,v -g shape then sort -f shape data/colored-shapes.dkvp
-shape    flag_min flag_mean flag_max u_min    u_mean   u_max    v_min     v_mean   v_max
-circle   0.000000 0.399846  1.000000 0.000044 0.498555 0.999923 -0.092709 0.495524 1.072500
-square   0.000000 0.396112  1.000000 0.000188 0.499385 0.999969 0.000089  0.496538 0.999975
-triangle 0.000000 0.401542  1.000000 0.000881 0.496859 0.999661 0.000717  0.501050 0.999995
-</pre>
-</div>
-<p/>
-
-<p/> Look at bivariate stats by color and shape. In particular, <tt>u,v</tt> pairwise correlation for red circles pops out:
-<p/>
-<div class="pokipanel">
-<pre>
-$ mlr --opprint --right stats2 -a corr -f u,v,w,x data/colored-shapes.dkvp
-u_v_corr  w_x_corr
-0.133418 -0.011320
-</pre>
-</div>
-<p/>
-<p/>
-<div class="pokipanel">
-<pre>
-$ mlr --opprint --right stats2 -a corr -f u,v,w,x -g color,shape then sort -nr u_v_corr data/colored-shapes.dkvp
- color    shape  u_v_corr  w_x_corr
-   red   circle  0.980798 -0.018565
-orange   square  0.176858 -0.071044
- green   circle  0.057644  0.011795
-   red   square  0.055745 -0.000680
-yellow triangle  0.044573  0.024605
-yellow   square  0.043792 -0.044623
-purple   circle  0.035874  0.134112
-  blue   square  0.032412 -0.053508
-  blue triangle  0.015356 -0.000608
-orange   circle  0.010519 -0.162795
-   red triangle  0.008098  0.012486
-purple triangle  0.005155 -0.045058
-purple   square -0.025680  0.057694
- green   square -0.025776 -0.003265
-orange triangle -0.030457 -0.131870
-yellow   circle -0.064773  0.073695
-  blue   circle -0.102348 -0.030529
- green triangle -0.109018 -0.048488
-</pre>
-</div>
-<p/>
-
-<a id="Program_timing"/><h1>Program timing</h1>
-
-This admittedly artificial example demonstrates using Miller time and stats
-functions to introspectly acquire some information about Miller&rsquo;s own
-runtime. The <tt>delta</tt> function computes the difference between successive
-timestamps.
-
-<p/>
-<div class="pokipanel">
-<pre>
-$ ruby -e '10000.times{|i|puts "i=#{i+1}"}' &gt; lines.txt
-
-$ head -n 5 lines.txt
-i=1
-i=2
-i=3
-i=4
-i=5
-
-mlr --ofmt '%.9le' --opprint put '$t=systime()' then step -a delta -f t lines.txt | head -n 7
-i     t                 t_delta
-1     1430603027.018016 1.430603027e+09
-2     1430603027.018043 2.694129944e-05
-3     1430603027.018048 5.006790161e-06
-4     1430603027.018052 4.053115845e-06
-5     1430603027.018055 2.861022949e-06
-6     1430603027.018058 3.099441528e-06
-
-mlr --ofmt '%.9le' --oxtab \
-  put '$t=systime()' then \
-  step -a delta -f t then \
-  filter '$i&gt;1' then \
-  stats1 -a min,mean,max -f t_delta \
-  lines.txt
-t_delta_min  2.861022949e-06
-t_delta_mean 4.077508505e-06
-t_delta_max  5.388259888e-05
-</pre>
-</div>
-<p/>
-    </div>
-  </td>
-
-</table>
-</body>
-</html>
+$ cat data/flins.csv | mlr --icsv --oxtab stats2 -a corr,linreg-ols,r2 -f tiv_2011,tiv_2012
\ No newline at end of file
diff --git a/doc/index.html b/doc/index.html
index e446f8ebe..fe3479860 100644
--- a/doc/index.html
+++ b/doc/index.html
@@ -125,7 +125,7 @@ positionally-indexed data as a special case.)
 <p/> Features:
 <ul>
 
-<li> I/O formats including <b>tabular pretty-printing</b>
+<li> I/O formats including <b>tabular pretty-printing</b> and <b>positionally indexed</b> (Unix-toolkit style)
 <li> <b>Conversion</b> between formats
 <li> <b>Format-aware processing</b>: e.g. CSV sort and tac keep header lines first
 <li> High-throughput <b>performance</b> on par with the Unix toolkit