Andreas, > But \prop_get_gdel:NNN doesn't work, yet. The value of the deleted > key is not assigned to the tlp. hmm, something got messed up when the prop implementation got changed from using sequences (with tlps) to toks registers. try this one \RequirePackage{l3prop} \ExplSyntaxOn \def_long:NNn \prop_get_del_aux:w 6 { \tlp_set:Nn #1{#5} \quark_if_no_value:NF #1 { \def:Npn \tmp:w ##1#3\q_no_value {#2{#4##1}} \tmp:w #6 } } i haven't updated it yet as I wonder why that change was done. using \quark_if_no_value:NF is much much faster than \quark_if_no_value:nF as the later literately scans for \q_no_value which the former just uses the quark feature that \tlp_set:Nn \FOO{\BAR} \if_meaning:NN \FOO \BAR -> true if and only if \BAR was a quark frank