diff --git a/.github/ISSUE_TEMPLATE/application.yml b/.github/ISSUE_TEMPLATE/application.yml
index d2007df..f64ea03 100644
--- a/.github/ISSUE_TEMPLATE/application.yml
+++ b/.github/ISSUE_TEMPLATE/application.yml
@@ -66,6 +66,33 @@ body:
     validations:
       required: true
 
+  - type: checkboxes
+    id: not-reference-architecture
+    attributes:
+      label: Project vs Reference Architecture/Implementation
+      description: |
+        **Is this a reusable open source project or a reference architecture/implementation?**
+
+        CNCF Sandbox accepts **reusable projects**, NOT reference architectures or reference implementations.
+
+        **Reusable project (eligible for Sandbox):**
+        - Generic, designed for broad adoption by any organization
+        - Provides reusable components, tools, or frameworks
+        - Can be integrated into different environments and use cases
+        - Focus is on solving a general problem, not demonstrating a specific architecture
+
+        **Reference architecture/implementation (NOT eligible - submit to [CNCF Reference Architectures](https://architecture.cncf.io/) instead):**
+        - Organization-specific implementation demonstrating cloud native patterns
+        - Company-specific platform or internal tooling
+        - Uses terms like "reference architecture", "reference implementation", "implementation of", or "persona-driven reference"
+        - Describes itself as an "implementation" showing how to use existing tools together
+        - Focus is on demonstrating patterns or wiring together existing tools rather than building a new reusable tool
+
+        **Key distinction:** If you're showing HOW to build something using existing tools (reference), vs building a NEW tool others can use (project).
+      options:
+        - label: This is a reusable open source project designed for broad adoption, not a reference architecture, reference implementation, or demonstration of patterns
+          required: true
+
   - type: markdown
     attributes:
       value: |
@@ -78,8 +105,22 @@ body:
   - type: input
     attributes:
       label: Org repo URL (provide if all repos under the org are in scope of the application)
-      description: Provide the URL of GitHub or Gitlab organization of the projects if all repos under the org are in scope of the application. If no organization, write "N/A".
-      placeholder: Add org URL here
+      description: |
+        Provide the URL of GitHub or GitLab organization of the projects if all repos under the org are in scope of the application. If no organization, write "N/A".
+
+        **⚠️ If you are a subproject separating from a parent project:**
+
+        If your project currently exists as part of another project's organization and you are applying to CNCF Sandbox separately, you MUST provide evidence of a **formal vote** by the parent project's maintainers approving your separation.
+
+        Include a link to a **public GitHub/GitLab issue** in the parent project's repository documenting the vote in the "Additional information" section at the end of this application.
+
+        **This requirement applies to ANY parent project, not just CNCF projects.**
+
+        **Example:** If your repo is under `https://github.com/parent-project-org/your-subproject` and you're applying separately from the parent project, you must link to an issue like:
+        `https://github.com/parent-project-org/parent-repo/issues/123`
+
+        This issue should show parent project maintainer consensus approving your move out of their organization to become a separate CNCF project.
+      placeholder: Add org URL here or N/A
     validations:
       required: true
 
@@ -149,11 +190,52 @@ body:
   - type: input
     attributes:
       label: Maintainers file
-      description: Provide the URL of the project's maintainers file or [`.project` repo](https://contribute.cncf.io/blog/2026/04/22/introducing-dot-project-for-maintainers).
-      placeholder: Add maintainer URL here
+      description: |
+        Provide the URL to your MAINTAINERS.md, MAINTAINERS, or [`.project` repo](https://contribute.cncf.io/blog/2026/04/22/introducing-dot-project-for-maintainers).
+
+        **Requirements:**
+        - Must be a direct GitHub link to the file (e.g., `https://github.com/org/repo/blob/main/MAINTAINERS.md`)
+        - File must contain a table with columns for: Name, GitHub ID, and **Company/Organization**
+        - Minimum **3 maintainers from 2+ different organizations** (see organization diversity note below)
+
+        **Invalid examples that will result in application closure:**
+        - ❌ Contributors graph: `https://github.com/org/repo/graphs/contributors`
+        - ❌ "N/A", "TBD", or "Will be added after acceptance"
+        - ❌ Links to external documentation websites (not on GitHub)
+        - ❌ Repository URL without direct `/blob/` path to the file
+
+        **Valid example format:**
+        ```markdown
+        | Maintainer | GitHub ID | Company/Organization |
+        | ---------- | --------- | -------------------- |
+        | Jane Doe   | @janedoe  | Acme Corp            |
+        | John Smith | @jsmith   | Example Inc          |
+        | Alice Lee  | @alee     | Demo Systems         |
+        ```
+      placeholder: https://github.com/your-org/your-repo/blob/main/MAINTAINERS.md
     validations:
       required: true
 
+  - type: markdown
+    attributes:
+      value: |
+        > [!IMPORTANT]
+        > **Organization Diversity Requirement**
+        >
+        > CNCF Sandbox requires **3+ maintainers from 2+ different organizations** (employers/companies).
+        >
+        > **What counts as different organizations:**
+        > - ✅ Different employers: Acme Corp, Example Inc, Demo Systems
+        > - ✅ Different legal entities: Google, Red Hat, Microsoft, Solo.io
+        >
+        > **What does NOT count:**
+        > - ❌ Different GitHub organizations (kubernetes, prometheus, envoy) - these are project orgs, not employers
+        > - ❌ Maintainers who all work for the same company but are members of different OSS GitHub orgs
+        >
+        > **Why this matters:** CNCF projects must be vendor-neutral. Single-vendor projects should mature to multi-organization governance before applying.
+        >
+        > **How to demonstrate:** Include a "Company" or "Organization" column in your MAINTAINERS file showing each maintainer's employer.
+
   - type: input
     attributes:
       label: Security policy file
@@ -275,8 +357,26 @@ body:
   - type: textarea
     attributes:
       label: Will the project require a license exception?
-      description: Does this project use a license other than [Apache 2.0 or one of the approved licenses on the CNCF Allowlist](https://github.com/cncf/foundation/blob/main/policies-guidance/allowed-third-party-license-policy.md#cncf-allowlist-license-policy)? If no, write "N/A".
-      placeholder: Add details on whether this project uses a license that is not on the approved list and therefore may need an exception after joining the CNCF
+      description: |
+        Does this project use a license other than [Apache 2.0 or one of the approved licenses on the CNCF Allowlist](https://github.com/cncf/foundation/blob/main/policies-guidance/allowed-third-party-license-policy.md#cncf-allowlist-license-policy)?
+
+        **⚠️ CRITICAL:** Your project's license must be compliant **BEFORE** acceptance. The TOC cannot accept projects with promises to "convert the license after acceptance."
+
+        **Allowed licenses:**
+        - ✅ **Apache 2.0** (strongly preferred for main project code)
+        - ✅ MIT, BSD-2-Clause, BSD-3-Clause, ISC (allowlist - may require migration to Apache 2.0 for main project code)
+        - See [full allowlist](https://github.com/cncf/foundation/blob/main/policies-guidance/allowed-third-party-license-policy.md)
+
+        **Not allowed (will result in application closure):**
+        - ❌ GPL, LGPL, AGPL (copyleft licenses)
+        - ❌ BSL / BUSL (Business Source License)
+        - ❌ Proprietary or custom licenses
+        - ❌ "We will convert to Apache 2.0 upon acceptance"
+
+        If your license is not on the allowlist, you must convert to Apache 2.0 BEFORE applying. Governing Board exceptions are rarely granted.
+
+        **If no exception needed, write "N/A".**
+      placeholder: N/A - Project uses Apache 2.0 license
     validations:
       required: true
 
@@ -292,6 +392,40 @@ body:
       value: |
         <br />
 
+        ---
+
+        ## ✅ Pre-Submission Checklist
+
+        Before submitting, verify your application meets these requirements:
+
+        **Critical Requirements (application will be closed if any are missing):**
+        - [ ] Project uses **Apache 2.0** or a [CNCF allowlist license](https://github.com/cncf/foundation/blob/main/policies-guidance/allowed-third-party-license-policy.md) (not "will convert later")
+        - [ ] **MAINTAINERS file** exists with Name, GitHub ID, and **Company/Organization** columns
+        - [ ] **3+ maintainers** from **2+ different organizations** (employers, not GitHub orgs)
+        - [ ] Direct link to MAINTAINERS file provided (not contributors graph, not "N/A")
+        - [ ] Repository is **6+ months old** with active development
+        - [ ] If separating from a parent project: public vote issue from parent project maintainers linked
+        - [ ] Project is **reusable**, not a reference architecture, reference implementation, or company-specific platform
+
+        **Recommended (improves review experience):**
+        - [ ] Code of Conduct, Contributing guide, Security policy properly documented
+        - [ ] Adopters list with production users
+        - [ ] Roadmap shows future direction and is publicly accessible
+        - [ ] Similar projects section addresses overlap and differentiation
+
+        **Common mistakes that result in auto-closure:**
+        - ❌ Linking to contributors graph instead of MAINTAINERS.md file
+        - ❌ All maintainers from same company (even if in different GitHub orgs)
+        - ❌ License not compliant (BSL, GPL, or promise to convert later)
+        - ❌ Repository younger than 6 months
+        - ❌ Saying "will add [required file] after acceptance"
+        - ❌ Reference architecture or reference implementation submitted as a project
+
+        <br />
+
+  - type: markdown
+    attributes:
+      value: |
         ## :envelope: Contact information
 
         Provide information about who to contact with questions about the project and who will sign the [Contribution Agreement](https://github.com/cncf/foundation/blob/main/agreements/Sample%20Contribution%20Agreement%20(2025).pdf).
diff --git a/README.md b/README.md
index e5d21c0..a45f4b9 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,38 @@ Applying is as easy as 1-2-3!
 > [!CAUTION]
 > The TOC MUST vote to approve your application and a [Contribution Agreement](https://github.com/cncf/foundation/blob/main/agreements/Sample%20Contribution%20Agreement%20(2025).pdf) MUST be signed before your project can be considered an official CNCF project. You can not represent your project as "donated" or "contributed" until those steps are completed. Please read more below.
 
+### Before you apply: Common reasons applications are closed
+
+Many applications are closed without TOC review due to not meeting basic eligibility criteria. Review these requirements before applying to avoid wasted effort:
+
+**✅ License Compliance**
+- Must use Apache 2.0 or a [CNCF allowlist license](https://github.com/cncf/foundation/blob/main/policies-guidance/allowed-third-party-license-policy.md)
+- License must be compliant **before** acceptance (promises to "convert after acceptance" are not accepted)
+- BSL (Business Source License) and GPL family licenses are not acceptable
+- **License exceptions:** If you believe your project is a good fit despite using a non-allowlist license, you may [request a license exception](https://contribute.cncf.io/projects/submit-license-exception-request/) from the CNCF Governing Board. Note: exceptions are rarely granted and require Governing Board approval.
+
+**✅ MAINTAINERS File**
+- Must provide direct link to MAINTAINERS.md or MAINTAINERS file (GitHub `/blob/` or GitLab path)
+- Cannot link to contributors graph, external website, or say "N/A" / "will be added"
+- File must contain table with: Name, ID, **Company/Organization** columns
+- Company/Organization column demonstrates employer diversity
+
+**✅ Organization Diversity**
+- Minimum **3 maintainers from 2+ different organizations** (employers)
+- "Organization" = employer/company, NOT GitHub/GitLab organization memberships
+- All maintainers from same company = single organization (does not meet requirement)
+- Being members of different GitHub orgs does not count as organization diversity
+
+**✅ Subproject Separation**
+- If your project is under another project's GitHub/GitLab organization, you must provide a link to a **public issue** in the parent project's repository showing maintainer consensus to split into separate CNCF project
+- Applies to ANY parent project (not just CNCF projects)
+
+**✅ Project vs Reference Architecture**
+- CNCF Sandbox accepts reusable projects, not reference architectures or implementations
+- If your project shows how to wire together existing tools (not building new tool), submit to [CNCF Reference Architectures](https://architecture.cncf.io/)
+
+For detailed requirements and examples, review the [application form](https://github.com/cncf/sandbox/issues/new?assignees=&labels=New&projects=&template=application.yml&title=%5BSandbox%5D+%3CProject+Name%3E) which includes inline guidance.
+
 ## What's next?
 
 Your project's application is placed in the backlog for triaging. You can view the status of your application and others at anytime by checking out our [Project Board](https://github.com/orgs/cncf/projects/14).