Vaakasuorien

Could you specify what vaakasuorien refers to? The term does not have a widely recognized meaning in standard Finnish references, so I want to avoid inventing details. If you can indicate the intended domain (for example, engineering/architecture, linguistics, geography, culture, or a fictional concept), I can draft a concise, neutral wiki-style article under 300 words. If you prefer, I can also produce a generic stub that treats vaakasuorien as a hypothetical term meaning “horizontals” in a neutral, context-free way. Please provide the intended context.