I got stuck on tutorial

[vitamin]

Oh, I see now (or at least, I hope I'm beginning to understand this). So this subdivision tool can be compared to, for example mesh smooth modifier in Max - am I right?

BTW, could you tell me please why Glen Southern wrote about box modeling (so the technique that Wings 3D uses) that we might have difficulties when working with blueprints? Here's a quote from his article 3D Primer :

Quote: It is not as easy to work with background reference images for this type of modeling