# Annotations

Sometimes you'll need to create milestones or threshold lines. This is possible by creating annotations for dimensions. You can created dynamic or static annotations via the dimension popup. Please see the examples below.

![](/files/-LB5uYztqBplOhuAnA2m)

The following math and statistical functions are available for numeric annotations:

## SUM(numerical expression)

Returns the sum of a series of numbers.

## AVG(numerical expression)

Returns the average of a series of numbers.

## MIN(numerical expression)

Returns the minimum of a series of numbers.

## MAX(numerical expression)

Returns the maximum of a series of numbers.

## MEDIAN(numerical expression)

Returns the number in the middle of a set of numbers.

## STDEV(numerical expression)

Estimates standard deviation based on a sample. The standard deviation is a measure of how widely values are dispersed from the average value (the mean).


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://trello-guide.vizydrop.com/annotations.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.