diff --git a/MAINTAINERS.md b/MAINTAINERS.md
index 9b865c022..12fb8012b 100644
--- a/MAINTAINERS.md
+++ b/MAINTAINERS.md
@@ -63,6 +63,4 @@ Therefore:
 * If a series of changes are being made or several pull requests are being merged at once, the PDF updates can be batched up and just made once at the end.
 * Conversely, if there are changes pending to several (even unrelated) PDFs, there is no reason not to commit them all at once.
 
-If you are working on several PDFs at once, be careful in step 3 and perhaps use `make clean new/VCFv4.2.pdf new/VCFv4.3.pdf; make VCFv4.2.pdf VCFv4.3.pdf` to ensure that spurious “-dirty” commit hashes don't make their way into your PDFs.
-
 <!-- vim:set linebreak: -->
diff --git a/Makefile b/Makefile
index a5a06bdae..fc24e4b71 100644
--- a/Makefile
+++ b/Makefile
@@ -30,8 +30,12 @@ new/%.pdf: %.tex
 	pdflatex --output-directory new $<
 	while grep -q 'Rerun to get [a-z-]* right' new/$*.log; do pdflatex --output-directory new $< || exit; done
 
+new/CRAMv2.1.ver new/CRAMv3.ver: img/CRAMFileFormat2-1-fig001.png img/CRAMFileFormat2-1-fig002.png img/CRAMFileFormat2-1-fig003.png img/CRAMFileFormat2-1-fig004.png img/CRAMFileFormat2-1-fig005.png img/CRAMFileFormat2-1-fig006.png img/CRAMFileFormat2-1-fig007.png
+
+new/VCFv4.1.ver new/VCFv4.2.ver new/VCFv4.3.ver: img/all_orientations-400x296.png img/derivation-400x267.png img/erosion-400x211.png img/inserted_contig-400x247.png img/inserted_sequence-400x189.png img/inversion-400x95.png img/microhomology-400x248.png img/multiple_mates-400x280.png img/phasing-400x259.png img/reciprocal_rearrangement-400x192.png img/telomere-400x251.png
+
 new/%.ver: %.tex
-	echo "@newcommand*@commitdesc{`git describe --always --dirty`}@newcommand*@headdate{`git rev-list -n1 --format=%aD HEAD $< | sed '1d;s/.*, *//;s/ *[0-9]*:.*//'`}" | tr @ \\ > $@
+	./genversion.sh $^ > $@
 
 
 mostlyclean:
diff --git a/_config.yml b/_config.yml
index fccf7e4b0..8f191b38f 100644
--- a/_config.yml
+++ b/_config.yml
@@ -7,7 +7,7 @@ description: >
 baseurl: "/hts-specs"
 url: "http://samtools.github.io"
 github_username: samtools
-exclude: ["*.tex", img, new, Makefile, MAINTAINERS.md, README.md]
+exclude: ["*.sh", "*.tex", img, new, Makefile, MAINTAINERS.md, README.md]
 
 # Build settings
 markdown: kramdown
diff --git a/genversion.sh b/genversion.sh
new file mode 100755
index 000000000..e7527da14
--- /dev/null
+++ b/genversion.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+# Add "-dirty" only if any of *this* PDF's source files is dirty
+test -n "$(git status --porcelain "$@")" && dirty=-dirty
+
+git rev-list -n1 --format='date %cD' HEAD -- "$@" | while read key value
+do
+    case $key in
+    commit)
+        value=$(git describe --always $value)
+        echo "@newcommand*@commitdesc{$value$dirty}"
+        ;;
+    date)
+        # Cut unwanted fields from "[Day, ]DD Mon YYYY[ HH:MM:SS +ZZZZ]"
+        value=$(echo $value | sed 's/.*, *//;s/ *[0-9]*:.*//')
+        echo "@newcommand*@headdate{$value}"
+        ;;
+    esac
+done | tr @ \\