diff --git a/reqs/.doorstop.yml b/reqs/.doorstop.yml
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--- /dev/null
+++ b/reqs/.doorstop.yml
@@ -0,0 +1,17 @@
+attributes:
+  defaults:
+    rationale: null
+    type: Requirement
+    verified-by: unverified
+    verified-comment: unverified
+    verified-date: unverified
+  publish:
+  - verified-by
+  - verified-date
+  - verified-comment
+  - type
+  - rationale
+settings:
+  digits: 4
+  prefix: REQ
+  sep: '-'
diff --git a/reqs/.gitignore b/reqs/.gitignore
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index 0000000..2a1683c
--- /dev/null
+++ b/reqs/.gitignore
@@ -0,0 +1,5 @@
+csv_files/
+*.csv
+*.tsv
+*.xlsx
+public/
\ No newline at end of file
diff --git a/reqs/README.md b/reqs/README.md
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index 0000000..a323eb4
--- /dev/null
+++ b/reqs/README.md
@@ -0,0 +1,213 @@
+# Requirements
+
+## Table of Contents
+
+- [Dependencies](#dependencies)
+- [Layout](#layout)
+- [Requirement Files](#requirement-files)
+- [How to Validate the Requirements](#how-to-validate-the-requirements)
+- [How to Export Requirements](#how-to-export-requirements)
+- [How to Add a Requirement Category](#how-to-add-a-requirement-category)
+- [How to Add a Requirement](#how-to-add-a-requirement)
+- [How to View Requirements](#how-to-view-requirements)
+
+## Dependencies
+
+```python3
+pip3 install doorstop pyyaml
+```
+
+Requirements are managed with [doorstop](https://doorstop.readthedocs.io/en/latest/).
+
+The `doorstop` command can be run in any directory, but this README assumes the current directory is `reqs/`.
+
+## Layout
+
+The top level requirement directory is `reqs`. The requirements in this repository are the highest level platform requirements. They have the prefix `REQ`.
+
+Lower level requirement locations:
+- Software-related: `SW/`
+- Electronics-related: `HW/`
+- Mechanical-related: `MECH`
+- Project directives: `PROJ/`
+
+An example layout of requirements is below.
+```tree
+.
+├── build
+├── REQ-0001.yml
+├── PROJ
+│   └── PROJ-0001.yml
+├── HW
+    └── HW-0001.yml
+│   └── FLIGHT
+│       └── FLIGHT-0001.yml
+└── SW
+    └── SW-0001.yml
+    ├── CMD_SVC
+    │   ├── CMD_SVC-0001.yml
+    ├── HEALTH_SVC
+    │   ├── HEALTH_SVC-0001.yml
+    └── TLM_SVC
+        ├── TLM_SVC-0001.yml
+```
+
+## Requirement Files
+
+The requirements are individual `.yml` files. Each contains the requirement's primary text as well as metadata.
+
+```yml
+# reqs/SW/HEALTH/HEALTH_SVC-0001.yml
+active: true
+derived: false
+header: ''
+level: 1.0
+links:
+- SW-0001: bBkf6YMFHFULHe5eLcjSBipaMvJL7t5BdNTRJdS-4Ug=
+normative: true
+rationale: |
+  If a device is acting offnominally, the software manager in charge of that device may elect to mark it as SICK or DEAD
+   to prevent accidental further usage.
+ref: ''
+reviewed: 7Pi6ZnjoRSEqcevT_DevP6N0liXRQPDnPh1W4QYxSz4=
+text: |
+  HEALTH_SVC shall provide an interface to mark a device as HEALTHY, SICK, or DEAD.
+```
+
+Important Field | Description
+---- | ---
+`text` | The primary text of the requirement
+`rationale` | Why the requirement exists, explanation of values in requirement, etc. This is a required field and is enforced with the `build` script.
+`links` | Links to parent requirements. In this case SW-0001 (*The platform shall maintain the health status of each device*) is the parent requirement. **All lower level requirements must have a parent.** This is enforced with the `build` script.
+`active` | If the requirement is in draft and you don't want to cause build errors, set this to `false`.
+
+
+## How to Validate the Requirements
+
+Use the `reqs/build` script.
+
+`reqs/build` will call:
+- `doorstop_yml_formatter.yml`
+  - Enforces the existence of the following fields: `verified-by`, `verified-date`, `verified-comments`, `type`, `rationale`
+  - Sets all parent link signatures to `null`
+      - `doorstop_hooks.py` will regenerate all signatures
+      - This avoids common "suspect link" error
+- `doorstop_hooks.py`
+  - A wrapper around `doorstop` with extra rules:
+    - `rationale` and `type` are required non-empty fields
+  - Will not check that all requirements have children (may be turned on later)
+  - Will not check for suspect links
+      - All parent link signatures were set to `null` in `doorstop_yml_formatter.py`
+  - Will regenerate link signatures
+  - Will reorder the `level` fields of documents to be consecutive
+- `doorstop publish all public/`
+- `doorstop export all ./csv_files/`
+
+An ideal build will look like so:
+
+```zsh
+➜  reqs git:(main) ✗ ./build
+building tree...
+loading documents...
+publishing tree to '/home/ams/gitprojects/arrowdrone-docs/reqs/REQ'...
+published: /home/ams/gitprojects/arrowdrone-docs/reqs/REQ
+building tree...
+loading documents...
+exporting tree to './csv_files'...
+exported: ./csv_files
+```
+
+Common errors and their fixes:
+
+Common Error | Fix
+--- | ---
+`EXAMPLE-0001: Rationale is required!` | Populate a `rationale` field in the requirement file.
+`EXAMPLE-0001: A parent is required for a lower level requirement!` | `doorstop link EXAMPLE-0001 PARENT-####`<br>Or manually update the `links` field in the requirement's `.yml`.
+`EXAMPLE-0001: suspect link` | Set the suspect link to `null` in the requirement's `.yml`
+`EXAMPLE-0001: unreviewed changes` | `doorstop review EXAMPLE-0001`.<br>Use `all` for resolving all reviews.
+`WARNING: no item with UID: EXAMPLE-0001` | This can happen if `active:false` in `EXAMPLE-0001.yml`.
+
+## How to Export Requirements
+
+You may be more comfortable with viewing requirements in an Excel spreadsheet.
+
+The `build` script should produce a `reqs/csv_files` directory.
+
+You can also run `doorstop export REQ path/to/tst.xlsx` (also supports tsv, csv, or yml), or similarly call it for any other requirement category.
+
+## How to Add a Requirement Category
+
+A requirement category can be added with `doorstop create`:
+
+```bash
+# doorstop create <category name> <path> --parent REQ
+$ doorstop create PWR ./HW/PWR --parent HW
+building tree...
+created document: PWR (@/reqs/HW/PWR)
+```
+
+You will see that a new directory was created and populated with a `.doorstop.yml` file:
+```yaml
+settings:
+  digits: 3
+  parent: HW
+  prefix: PWR
+  sep: ''
+```
+
+We have specific fields for this project. All `.doorstop.yml` files not following the project standard will be rectified when the `build` script is called.
+
+Output after `./build`:
+
+```yaml
+attributes:
+  publish:
+  - verified-by
+  - type
+  - rationale
+settings:
+  digits: 4
+  parent: HW
+  prefix: PWR
+  sep: '-'
+```
+
+If we build now, we will get a warning: `PWR: no items`.
+
+## How to Add a Requirement
+
+Requirements can be added with `doorstop add`:
+
+```bash
+# doorstop add <category>
+$ doorstop add PWR
+building tree...
+added item: PWR-0001 (@/reqs/HW/PWR/PWR-0001.yml)
+```
+The new file can be manually populated with the required fields.
+
+You must then link the requirement to a parent requirement before the build can succeed:
+
+`doorstop link PWR-0001 HW-####`
+
+You can add multiple requirements add the same time with the `-c` option:
+
+```bash
+$ doorstop add PWR -c 3
+building tree...
+added item: PWR-0002 (@/reqs/HW/PWR/PWR-0002.yml)
+added item: PWR-0003 (@/reqs/HW/PWR/PWR-0003.yml)
+added item: PWR-0004 (@/reqs/HW/PWR/PWR-0004.yml)
+```
+
+## How to View Requirements
+
+To view the requirements outside of source code, do one of the following:
+1) `doorstop-server`
+    - Visit `localhost:7867` in your browser
+2) `cd public/; python -m http.server PORT` 
+    - Visit `localhost:PORT` in your browser
+3) `doorstop-gui`
+    - tkinter application
+4) TODO: Visit arrowair.com arrowdrone subdir
+5) Open the csv file(s) in Excel.
\ No newline at end of file
diff --git a/reqs/build b/reqs/build
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index 0000000..25a5971
--- /dev/null
+++ b/reqs/build
@@ -0,0 +1,23 @@
+#!/bin/bash
+
+CSV=csv_files
+
+python3 doorstop_yml_formatter.py
+if [ $? -ne 0 ]; then
+    echo "FAILURE, exiting build."
+    exit 1
+fi
+
+# doorstop --no-suspect-check --reorder --no-child-check
+python3 doorstop_hooks.py
+if [ $? -eq 0 ]; then
+    rm -rf public
+    doorstop publish all public/ # This may not scale
+    rm -rf ./$CSV
+    doorstop export all ./$CSV # This may not scale
+else
+    echo "FAILURE, exiting build."
+    exit 1
+fi
+
+exit 0
\ No newline at end of file
diff --git a/reqs/doorstop_hooks.py b/reqs/doorstop_hooks.py
new file mode 100755
index 0000000..091379a
--- /dev/null
+++ b/reqs/doorstop_hooks.py
@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+
+
+import sys
+from doorstop import build, settings, DoorstopInfo, DoorstopWarning, DoorstopError
+
+# Reorder document `level` fields automatically if a REQ is deleted
+settings.REORDER = True
+
+# Parent links are set to null then regenerated every time with the ./build script
+# Don't need to check
+settings.CHECK_SUSPECT_LINKS = False
+
+# Not all requirements will have children
+settings.CHECK_CHILD_LINKS  = False
+
+def main():
+    tree = build()
+    success = tree.validate(document_hook=check_document, item_hook=check_item)
+    sys.exit(0 if success else 1)
+
+
+def check_document(document, tree):
+    if sum(1 for i in document if i.normative) < 10:
+        yield DoorstopInfo("fewer than 10 normative items")
+
+def check_item(item, tree, document):
+    if not item.get('rationale'):
+        yield DoorstopError("Rationale is required!")
+
+    if not item.get('type'):
+        yield DoorstopError("Type is required!")
+
+    uid = item.get('path').split('/')[-1]
+    if len(item.get('links')) == 0 and not uid.startswith('REQ'):
+        yield DoorstopError("A parent is required for a lower level requirement!")
+
+if __name__ == '__main__':
+    main()
\ No newline at end of file
diff --git a/reqs/doorstop_yml_formatter.py b/reqs/doorstop_yml_formatter.py
new file mode 100755
index 0000000..f62a0f6
--- /dev/null
+++ b/reqs/doorstop_yml_formatter.py
@@ -0,0 +1,111 @@
+#!/usr/bin/env python
+
+import os
+import sys
+import re
+import yaml
+
+# Constants
+# To appear in every .doorstop.yml
+DIGITS = 4
+SEPARATOR = '-'
+TYPE = 'Requirement'
+
+##
+## Helper
+##
+def failure(msg):
+    print("ERROR: %s. Failing %s." % (
+        msg, __file__
+    ))
+    sys.exit(1)
+
+def req_yaml_format(filename):
+    with open(filename, 'r') as f:
+        contents = yaml.safe_load(f)
+        if not contents:
+            failure("Unable to parse %s." % filename)
+
+        contents['type'] = TYPE
+        if not contents.get('rationale'):
+            contents['rationale'] = None
+
+        x = contents.get('verified-by')
+        if not x or x is None:
+            contents['verified-by'] = 'unverified'
+
+        x = contents.get('verified-date')
+        if not x or x is None:
+            contents['verified-date'] = 'unverified'
+    
+        x = contents.get('verified-comment')
+        if not x or x is None:
+            contents['verified-comment'] = 'unverified'
+
+        x = contents.get('links')
+        if x:
+            for count, item in enumerate(x):
+                for k, _ in item.items():
+                    contents['links'][count][k] = None
+
+    with open(filename, 'w') as yml_file:
+        yaml.dump(contents, yml_file)
+
+def doorstop_yaml_format(filename):
+    with open(filename, 'r') as f:
+        contents = yaml.safe_load(f)
+        if not contents:
+            failure("Unable to parse %s." % filename)
+        
+        if not contents.get('settings'):
+            contents['settings'] = {}
+
+        contents['settings']['sep'] = SEPARATOR
+        contents['settings']['digits'] = DIGITS
+
+        if not contents.get('attributes'):
+            contents['attributes'] = {}
+        
+        contents['attributes']['publish'] = [
+            'verified-by',
+            'verified-date',
+            'verified-comment',
+            'type',
+            'rationale'
+        ]
+
+        if not contents['attributes'].get('defaults'):
+            contents['attributes']['defaults'] = {}
+
+        # Needs to be specific value
+        contents['attributes']['defaults']['type'] = TYPE
+        
+        # Default is None
+        if not contents['attributes']['defaults'].get('rationale'):
+            contents['attributes']['defaults']['rationale'] = None
+
+        # Default is "unverified"
+        l = [
+            'verified-by',
+            'verified-date',
+            'verified-comment',
+        ]
+        for item in l:
+            x = contents['attributes']['defaults'].get(item)
+            if not x or x is None:
+                contents['attributes']['defaults'][item] = 'unverified'
+
+
+    with open(filename, 'w') as yml_file:
+        yaml.dump(contents, yml_file)
+
+
+if __name__ == '__main__':
+    for root, subdirs, files in os.walk('.'):
+        for f in files:
+            if f == '.doorstop.yml':
+                doorstop_yaml_format(os.path.join(root, f))
+            elif re.search('[A-Z]+-[0-9]+.yml', f):
+                req_yaml_format(os.path.join(root, f))
+
+    sys.exit(0)
\ No newline at end of file