Also in Spain there are prohibitions on certain knife types. So are knives with an automatic opening mechanism. Butterfly knives and banned.
Particular emphasis is placed on so-called "Fantasy knives," i.e. knives with a particularly aggressive appearance. Hallmarks of this type of knife are for example [holes in the blade], [saw-back blades] and [sharpened spines]. These types of knives are prohibited.
Also prohibited are Karambits, and knives with a retaining hole on the handle, Stoßdolche ([Push dagger]?) and knives disguised as other objects. For example sword canes, knives hidden in pens
and the like.
Daggers are prohibited if the blade is shorter than 7 cm (2.76"). [NOTE: Short is illegal, but not long? whaaa?]
Folding knives (even with locking mechanism) are legal, provided that the blade length is less than 10 cm (3.94"). Possession of one-handed knives is allowed. The carrying and possession of fixed-blade knives are basically allowed. You need only ensure that during transportation,
that they are not directly accessible.
As in many other countries , the rule is that you should have a legal use for your knife, which does give you a certain amount of lattitude with police and other authorities.