# Diagram tabs

> Adding, naming and ordering the tabs across the top of a blueprint.

Tabs run across the top of a published blueprint and are the reader's main
navigation. The first is always a diagram.

## Adding

**Add tab** in step 1 offers the six kinds. The choice is fixed once content
exists in the tab.

## Naming

Tab names are the labels on the strip. Short nouns work: *Logical*, *Physical*,
*Runtime*, *Data*. Avoid restating the blueprint title in every tab.

> [!TIP]
> A tab strip is easy to miss. If a later tab holds something essential, say
> so in the first tab's prose.

## Ordering

Drag to reorder. The first tab must remain a diagram: the editor will not let
you drag a prose tab into first position.

## Engines

Each diagram tab has its own engine, and a blueprint can mix them: a Vellum
context diagram, a Mermaid sequence diagram, and an imported draw.io network
diagram in one document.
[draw.io, Excalidraw and Mermaid](/foliums/blueprintr-user-guide/vellum/draw-io-excalidraw-and-mermaid)
covers the non-Vellum engines.

## Limits

There is a hard ceiling on tabs per blueprint. If you are close to it, split
the content into several blueprints in a
[portfolio](/foliums/blueprintr-user-guide/organise/portfolios-and-folders), or move
it into a [folium](/foliums/blueprintr-user-guide/foliums).