diff --git a/CHANGELOG.md b/CHANGELOG.md
index f008bb9..a8ed54d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,10 +20,12 @@
 ### Added
 
 1. Add encode/decode pldmMessagePollEvent data
+2. README: Add a section on working with libpldm
 
 ### Changed
 
 1. include: Move installed transport.h under libpldm/
+2. libpldm: Explicit deprecated, stable and testing ABI classes
 
 ### Fixed
 
diff --git a/README.md b/README.md
index d3b6611..91f9ace 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,120 @@
 meson setup builddir && meson test -C builddir
 ```
 
+## Working with `libpldm`
+
+The ABIs (symbols, generally functions) exposed by the library are separated
+into three categories:
+
+1. Stable
+2. Testing
+3. Deprecated
+
+Applications depending on `libpldm` should aim to only use functions from the
+stable category. However, this may not always be possible. What to do when
+required functions fall into the deprecated or testing categories is outlined
+below.
+
+### The ABI lifecycle
+
+```mermaid
+---
+title: libpldm symbol lifecycle
+---
+stateDiagram-v2
+    direction LR
+    [*] --> Testing: Add
+    Testing --> Testing: Change
+    Testing --> [*]: Remove
+    Testing --> Stable: Stabilise
+    Stable --> Deprecated: Deprecate
+    Deprecated --> [*]: Remove
+```
+
+The ABI of the library produced by the build is controlled using the `abi` meson
+option. The following use cases determine how the `abi` option should be
+specified:
+
+| Use Case    | Meson Configuration               |
+| ----------- | --------------------------------- |
+| Production  | `-Dabi=deprecated,stable`         |
+| Maintenance | `-Dabi=stable`                    |
+| Development | `-Dabi=deprecated,stable,testing` |
+
+### Maintenance
+
+Applications and libraries that depend on `libpldm` can identify how to migrate
+off of deprecated APIs by constraining the library ABI to the stable category.
+This will force the compiler identify any call-sites that try to link against
+deprecated symbols.
+
+### Development
+
+Applications and libraries often require functionality that doesn't yet exist in
+`libpldm`. The work is thus in two parts:
+
+1. Add the required APIs to `libpldm`
+2. Use the new APIs from `libpldm` in the dependent application or library
+
+Adding APIs to a library is a difficult task. Generally, once an API is exposed
+in the library's ABI, any changes to the API risk breaking applications already
+making use of it. To make sure we have more than one shot at getting an API
+right, all new APIs must first be exposed in the testing category. Concretely:
+
+Patches adding new APIs MUST mark them as testing and MUST NOT mark them as
+stable.
+
+### Marking functions as testing, stable or deprecated
+
+Three macros are provided through `config.h` to mark functions as testing,
+stable or deprecated:
+
+1. `LIBPLDM_ABI_TESTING`
+2. `LIBPLDM_ABI_STABLE`
+3. `LIBPLDM_ABI_DEPRECATED`
+
+These annotations go immediately before your function signature:
+
+```c
+#include "config.h"
+
+...
+
+LIBPLDM_ABI_TESTING
+pldm_requester_rc_t pldm_transport_send_msg(struct pldm_transport *transport,
+					    pldm_tid_t tid,
+					    const void *pldm_req_msg,
+					    size_t req_msg_len)
+{
+    ...
+}
+```
+
+### Requirements for stabilising a function
+
+As mentioned above, all new functions must first be added in the testing
+category (using the `LIBPLDM_ABI_TESTING` annotation).
+
+To move a function from the testing category to the stable category, its
+required that patches demonstrating use of the function in a dependent
+application or library be linked in the commit message of the stabilisation
+change. We require this to demonstrate that the implementer has considered its
+use in context _before_ preventing us from making changes to the API.
+
+### Building a dependent application or library against a testing ABI
+
+Meson is broadly used in the OpenBMC ecosystem, the historical home of
+`libpldm`. Meson's subprojects are a relatively painless way of managing
+dependencies for the purpose of developing complex applications and libraries.
+Use of `libpldm` as a subproject is both supported and encouraged.
+
+`libpldm`'s ABI can be controlled from a parent project through meson's
+subproject configuration syntax:
+
+```shell
+$ meson setup ... -Dlibpldm:abi=deprecated,stable,testing ...
+```
+
 ## OEM/vendor-specific functions
 
 This will support OEM or vendor-specific functions and semantic information.