Hi, Weak vectors are documented in ‘6.17.3.2 Weak vectors’. However, they are not available from the (guile) module and that section does not document which module needs to be imported to use the procedures from that section. I only found the required module (ice-9 weak-vector) by doing $ git grep -F 'make-weak-vector' It would be nice to document the module name, and not only the procedures theirselves. Greetings, Maxime.