Hi all: I have that problem that I get some unwanted optimizations from format : I want to do send a string to Tcl/Tk via function tk-format-now. My call to tk-format-now looks as follows: (tk-format-now "fileevent ~A readable [list readable ~A ~A]" ch-name ch-name path)) This produces a Tcl error: Tcl error: can not find channel named "#1=file22" [Condition of type SIMPLE-ERROR] When looking at the call stack then I see the followig: 6: (CTK::TCL-EVAL-EX 25144328 "fileevent #1=file22 readable [list readable #1# .fileevent-test]") Locals: CTK::I = 25144328 CTK::S = "fileevent #1=file22 readable [list readable #1# .fileevent-test]" 7: (CTK:TK-FORMAT-NOW "fileevent ~A readable [list readable ~A ~A]" #1="file22" #1# ".fileevent-test") Locals: CTK::FMT$ = "fileevent ~A readable [list readable ~A ~A]" NIL = "file22" NIL = "file22" NIL = ".fileevent-test" Obviously Lisp optimizes the reference to the string object "file22" into a reference (Hmm - this is new to me. Is this real Lisp speak to describe the facts shown above ???). Thx for any pointers! Frank