Souvlaki (Thessaloniki Usage) is not a sandwich but a piece of vocabulary that changes what you get when you order. In Thessaloniki, the word souvlaki refers to any meat in a pita, whether it came off a vertical cone or off a skewer. This is the opposite of the convention elsewhere, where souvlaki implies the skewer and the cone-shaved meat is named separately. Walk into a Thessaloniki shop and ask for a souvlaki and you have specified the format, bread with meat, but not the meat's source, which is the detail that actually decides what lands in your hand.
The fix is built into how locals order, and it is worth knowing precisely. To get the rotisserie-shaved meat, the kind carved off a turning vertical spit, you ask for it apo gyro, from the cone. To get the skewered, char-grilled cubes, you ask for it apo kalamaki, from the skewer. Those two phrases are the whole solution. Said correctly, you get exactly the texture you wanted: the soft, fatty, crisp-edged shavings of the cone, or the firmer, smokier, char-cornered cubes of the stick. Said vaguely, or assuming the southern convention, you risk a mismatch, ordering what you think is the skewer and receiving cone meat, or the reverse, because in this city the bare word does not carry that information. The good outcome is simply getting the meat you intended; the failure is a needless surprise that comes entirely from not knowing the local rule.
This terminology gap is why the regional usage deserves its own explainer rather than being folded into any single sandwich entry. The skewered kalamaki and its wrapped pita form are their own dishes and deserve their own articles rather than being crowded in here, as does the cone-shaved gyros. What this entry exists to record is narrow and practical: that in Thessaloniki souvlaki is a category covering both, and that apo gyro and apo kalamaki are the two phrases that turn a vague order into the exact thing you wanted.