diff --git a/README.md b/README.md
index 5d616c6c..af82ab7f 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,10 @@ core applications: https://status.twinnation.org/
 - [Usage](#usage)
   - [Configuration](#configuration)
   - [Conditions](#conditions)
+    - [Placeholders](#placeholders)
+    - [Functions](#functions)
+      - [Length - len()](#length---len)
+      - [Pattern - pat()](#pattern---pat)
   - [Alerting](#alerting)
     - [Configuring Slack alerts](#configuring-slack-alerts)
     - [Configuring PagerDuty alerts](#configuring-pagerduty-alerts)
@@ -75,7 +79,7 @@ Note that you can also add environment variables in the configuration file (i.e.
 ### Configuration
 
 | Parameter                                | Description                                                                   | Default        |
-| ---------------------------------------- | ----------------------------------------------------------------------------- | -------------- |
+|:---------------------------------------- |:----------------------------------------------------------------------------- |:-------------- |
 | `debug`                                  | Whether to enable debug logs                                                  | `false`        |
 | `metrics`                                | Whether to expose metrics at /metrics                                         | `false`        |
 | `services`                               | List of services to monitor                                                   | Required `[]`  |
@@ -114,23 +118,64 @@ Note that you can also add environment variables in the configuration file (i.e.
 Here are some examples of conditions you can use:
 
 | Condition                    | Description                                             | Passing values             | Failing values |
-| -----------------------------| ------------------------------------------------------- | -------------------------- | -------------- |
+|:-----------------------------|:------------------------------------------------------- |:-------------------------- | -------------- |
 | `[STATUS] == 200`            | Status must be equal to 200                             | 200                        | 201, 404, ...  |
 | `[STATUS] < 300`             | Status must lower than 300                              | 200, 201, 299              | 301, 302, ...  |
 | `[STATUS] <= 299`            | Status must be less than or equal to 299                | 200, 201, 299              | 301, 302, ...  |
 | `[STATUS] > 400`             | Status must be greater than 400                         | 401, 402, 403, 404         | 400, 200, ...  |
 | `[RESPONSE_TIME] < 500`      | Response time must be below 500ms                       | 100ms, 200ms, 300ms        | 500ms, 501ms   |
-| `[BODY] == 1`                | The body must be equal to 1                             | 1                          | Anything else  |
+| `[IP] == 127.0.0.1`          | Target IP must be 127.0.0.1                             | 127.0.0.1                  | 0.0.0.0        |
+| `[BODY] == 1`                | The body must be equal to 1                             | 1                          | `{}`, `2`, ... |
 | `[BODY].user.name == john`   | JSONPath value of `$.user.name` is equal to `john`      | `{"user":{"name":"john"}}` |  |
 | `[BODY].data[0].id == 1`     | JSONPath value of `$.data[0].id` is equal to 1          | `{"data":[{"id":1}]}`      |  |
+| `[BODY].age == [BODY].id`    | JSONPath value of `$.age` is equal JSONPath `$.id`      | `{"age":1,"id":1}`         |  |
 | `len([BODY].data) < 5`       | Array at JSONPath `$.data` has less than 5 elements     | `{"data":[{"id":1}]}`      |  |
 | `len([BODY].name) == 8`      | String at JSONPath `$.name` has a length of 8           | `{"name":"john.doe"}`      | `{"name":"bob"}` |
-| `[BODY].age == [BODY].id`    | JSONPath value of `$.age` is equal JSONPath `$.id`      | `{"user":{"name":"john"}}` |  |
+| `[BODY].name == pat(john*)`  | String at JSONPath `$.name` matches pattern `john*`     | `{"name":"john.doe"}`      | `{"name":"bob"}` |
+
+
+#### Placeholders
+
+| Placeholder                  | Description                                             | Example of resolved value  |
+|:---------------------------- |:------------------------------------------------------- |:-------------------------- |
+| `[STATUS]`                   | Resolves into the HTTP status of the request            | 404
+| `[RESPONSE_TIME]`            | Resolves into the response time the request took, in ms | 10
+| `[IP]`                       | Resolves into the IP of the target host                 | 192.168.0.232
+| `[BODY]`                     | Resolves into the response body. Supports JSONPath.     | `{"name":"john.doe"}`
+
+
+#### Functions
+
+##### Length - len()
+
+Returns the length of the object/slice.
+
+Example:
+```
+len([BODY].username) > 8
+```
+
+Works only with the `[BODY]` placeholder.
+
+
+##### Pattern - pat()
+
+Specifies that the string passed as parameter should be evaluated as a pattern.
+
+Usage:
+```
+[IP] == pat(192.168.*)
+```
+
+Works only with `==` and `!=` comparators.
+
+**NOTE**: Use patterns only when you need to. `[STATUS] == pat(2*)` is a lot more expensive than `[STATUS] < 300`.
+
+
 
 ### Alerting
 
 
-
 #### Configuring Slack alerts
 
 ```yaml