diff --git a/sheets/readelf b/sheets/readelf
new file mode 100644
index 0000000..bec2504
--- /dev/null
+++ b/sheets/readelf
@@ -0,0 +1,2 @@
+# How to check that an object file was built with -fPIC
+readelf --relocs foo.o | egrep '(GOT|PLT|JU?MP_SLOT)'