Purpose

This document defines the information architecture (IA) for maintaining a single documentation site that supports multiple product tiers/plans.

The goal is to:

  • Maintain one canonical documentation source
  • Avoid content duplication and drift
  • Provide clear visibility of feature availability per plan
  • Reduce user friction when navigating between tiers
  • Ensure documentation remains scalable as plans evolve

This architecture follows a Single Source of Truth (SSOT) model with conditional audience segmentation.


Core Architecture Principles

1. Single Source of Truth (SSOT)

All documentation lives in one unified doc site (zensical) rather than separate sites per plan.

Benefits:

  • Prevents content divergence
  • Reduces maintenance overhead
  • Simplifies search and navigation
  • Improves long-term maintainability

2. Trunk vs Branch Content Model

Documentation content is divided into two conceptual layers.

Trunk Content

Content applicable to all plans.

Characteristics:

  • Default content on the page
  • Represents the common workflow
  • Should make up the majority of the document

Rule:

Trunk content should represent at least 70% of the page.

Examples:

  • Feature overview
  • Basic configuration steps
  • Common workflows

Branch Content

Content that applies only to specific tiers/plans.

Characteristics:

  • Highlighted with tier indicators
  • Clearly separated from trunk content
  • Used only where feature differences exist

Examples:

  • Enterprise-only features
  • Plan-specific limits
  • Advanced configuration options

Multi-Dimensional Documentation Strategy

Documentation must account for multiple types of variation.

These variations are handled using two mechanisms:

Variation TypeMechanism
Workflow differencesTabs
Plan entitlementTier blocks

Tabs (Workflow Variations)

Tabs are used when users must choose between different procedures.

Example scenarios:

  • Different authentication methods
  • Different deployment environments
  • Different integration types

Example:


=== “SAML”

Steps for configuring SAML.


=== “OAuth”

Steps for configuring OAuth.

Guidelines:

  • Use when workflows are mutually exclusive
  • Maximum 2–3 tabs recommended
  • Avoid using tabs for pricing tier differences

Tier Blocks (Plan Differences)

Tier blocks are used when features are available only in specific plans.

Example:


::: tier enterprise master-plus

Advanced SAML configuration options are available.

:::

Purpose:

  • Inform users which plans support a feature
  • Avoid duplicating entire workflows
  • Preserve trunk content integrity

Tier Badges

Tier badges appear under the page title to indicate feature availability.

Example metadata:


---

## title: SSO Configuration

##   

## tiers: [enterprise, master-plus]

This allows users to quickly identify:

  • Which plans support the feature
  • Whether an upgrade may be required

When to Use Each Pattern

Use Trunk Content When

  • Instructions apply to all users
  • Feature is universally available
  • Differences are minimal

Use Tier Blocks When

  • Only a small section differs
  • Feature is plan-gated
  • Additional options exist for higher tiers

Use Tabs When

  • Workflows are fundamentally different
  • Users must select one path
  • Steps differ significantly

Architecture Rules

Rule 1 — Limit Tab Count

Tabs should not exceed:

3 per page

Too many tabs increase cognitive load.


Rule 2 — Protect Trunk Dominance

Branch content should remain limited.

If tier-specific content exceeds 30% of the page, consider:

  • Splitting the page
  • Creating a dedicated advanced guide

Rule 3 — Avoid Content Duplication

The same instructions should never appear in multiple tier sections.

Instead:

  • Place shared content in trunk
  • Add tier blocks for differences

Rule 4 — Ensure Edit Efficiency

If a workflow step changes, it should require editing no more than two locations.

If more edits are required, the architecture needs restructuring.


Example Page Structure


# SSO Configuration

  

[ Tier Badges ]

  

## Overview

  

Trunk explanation of SSO configuration.

  

## Authentication Method

  

=== “SAML”

Base SAML setup steps.

::: tier enterprise master-plus Advanced SAML configuration options. :::


=== “OAuth”

OAuth setup instructions.

This structure ensures:

  • Shared explanation remains centralized
  • Tier differences remain explicit
  • Workflow differences remain clear

Benefits of This Architecture

  • Reduces documentation duplication
  • Prevents content drift
  • Improves readability
  • Scales as plans evolve
  • Supports automated processing and future tooling

Future Scalability

This architecture supports future improvements such as:

  • Tier-aware documentation generation
  • Automated content validation
  • AI-assisted documentation search
  • Conditional content filtering

By structuring documentation around semantic content blocks, the system remains flexible for future tooling and automation.


Summary

The documentation architecture follows three core concepts:

  1. Single Source of Truth
  2. Trunk and Branch Content Model
  3. Hybrid Variation Handling (Tabs + Tier Blocks)

This approach enables scalable, maintainable documentation for multi-tier SaaS products while preserving clarity for users across all plans.