diff --git a/Makefile b/Makefile
index d471726..c4e2977 100644
--- a/Makefile
+++ b/Makefile
@@ -7,10 +7,17 @@ articles != find * -type f -name "*.md"
 
 db.rec: $(articles)
 	for x in $^ ; do \
-	sed -n '2,/^---$$/ {/^---$$/d; p}' "$$x" |\
-	tr -d '"[]' ;\
-	printf "file: %s\n\n" "$$x" ;\
+		sed -n '2,/^---$$/ {/^---$$/d; p}' "$$x" |\
+		sed -e 's/\[ //'  -e 's/ \]//' |\
+		tr -d '"' ;\
+		printf "file: %s\n\n" "$$x" ;\
 	done > $@
+	recsel $@ -e "requires != ''" -CR title,requires |\
+	while read title requires; do \
+		IFS=', ' && for provider in $$requires; do \
+			recset $@ -e "title = '$${provider}'" -f provides -a "$${title}" ;\
+		done ;\
+	done
 
 default += db.rec
 
@@ -32,6 +39,6 @@ article: ## Write an article
 	printf '%s\n\n' '---' >> $$path/$$title.md ;\
 	$(EDITOR) +5 $$path/$$title.md
 
-.PHONY: clean ## Remove all generated files
-clean:
+.PHONY: clean
+clean: ## Remove all generated files
 	$(RM) $(default)
diff --git a/distros/arch/basic-install.md b/distros/arch/basic-install.md
index 36ca460..1a610e2 100644
--- a/distros/arch/basic-install.md
+++ b/distros/arch/basic-install.md
@@ -1,6 +1,7 @@
 ---
 title: "basic-install"
 tags: [ "Documentation", "arch" ]
+requires: [ "partitions", "time" ]
 ---
 Keyboard layout changed.
 
diff --git a/networking/fail2ban.md b/networking/fail2ban.md
index 0d2ab5b..01ef19d 100644
--- a/networking/fail2ban.md
+++ b/networking/fail2ban.md
@@ -1,6 +1,7 @@
 ---
 title: "fail2ban"
 tags: [ "Documentation", "Networking" ]
+requires: [ "ssh" ]
 ---
 # SSH Daemon Jail
 
diff --git a/networking/ssh/sshfs.md b/networking/ssh/sshfs.md
index 7498b17..2a25233 100644
--- a/networking/ssh/sshfs.md
+++ b/networking/ssh/sshfs.md
@@ -1,6 +1,7 @@
 ---
 title: "sshfs"
 tags: [ "Documentation", "Networking" ]
+requires: [ "ssh" ]
 ---
 # Mount 
 
diff --git a/networking/ssh/tricks.md b/networking/ssh/tricks.md
index 574842e..0b8f575 100644
--- a/networking/ssh/tricks.md
+++ b/networking/ssh/tricks.md
@@ -1,6 +1,7 @@
 ---
-title: "ssh tricks"
+title: "ssh-tricks"
 tags: [ "Documentation", "Networking", "ssh", "tricks" ]
+requires: [ "ssh" ]
 ---
 
 Mount a remote filesystem locally with fuse-sshfs: