This is what I want (Sugarcube syntax):
where 301 and 35 are passage titles, where I need to go depending on the $oven value.
The resulting html DOES what I want, BUT displays it as if there were an error! It says: "This passage does not exist: " and then shows correctly the "non-existing" passage, all on pink background. How to fix this? (Surely I can write <<if $oven>>301
<<endif>>, but this is ugly.)