---
title: "Explanatory Hints"
slug: "explanatory-hints"
updated: 2026-04-24T14:55:30Z
published: 2026-04-24T14:55:30Z
---

> ## Documentation Index
> Fetch the complete documentation index at: https://kb.pigment.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Explanatory Hints

The formula bar provides hints that help you improve performance and understand automatic adjustments that Pigment has made on your formulas.

In some cases it warns about missing or unnecessary Dimensions, so that you can take appropriate action. In other cases it helps users’ understanding by providing context.

This page covers hints flagging formulas with `BY`, `IF` and arithmetic expressions. For other kinds of hints, see [Dimensionality Hints](/v1/docs/dimension-alignment-indicator) and [Performance Improvement Hints](/v1/docs/performance-hints).

## Find the hints

Hints are available when a 🛈 appears beside the ***⨍*** indicator or a light bulb appears. See the example below.

![](https://cdn.document360.io/e47cfe35-dc28-40c7-a083-6cf003073d8e/Images/Documentation/image-1773846953953.png)

## Dimension changes caused by BY

It is not always easy to understand which Dimensions will appear in the output after a [BY modifier](https://portal.document360.io/v1/docs/by-modifier) transformation. The Dimensionality Indicator light bulb appears when the Dimensions resulting from the transformation are different from the Metric’s Dimensions.

When you hover your pointer over the indicator, a pop-up opens showing all the hints for your formula. Select **Dimensions changes with BY modifier******to open details of any Dimensions that were automatically added or removed.

> [!NOTE]
> **ℹ️ Note**
> 
> If the Dimensions resulting from the transformation are the same as the Metric's Dimensions, no hint is displayed.

If no aggregation or allocation operator is specified in a formula featuring the `BY` modifier, the Dimensionality Indicator light bulb also appears. The hint explains which default operator (`SUM` or `CONSTANT`) was automatically added by Pigment.

For more information, see the Hints and Troubleshooting section of [BY modifier](/v1/docs/by-modifier#hints-and-troubleshooting).

## Dimension alignment in IF expressions

For formulas using an [IF expression](https://portal.document360.io/v1/docs/if-function), which have the “Value if true” argument specified, but the “Value if false or BLANK” argument not specified, the Dimensionality Indicator light bulb appears whenever the “Logical Test” argument uses Dimensions that are different from those involved in the “Value if true” argument.

The hints explain the output of the `IF` statement, when:

- The “Value if true” argument is a subset of the Logical Test.
- One argument’s Dimensions are neither a subset nor a superset of the other.
- The Logical Test involves Dimensions and “Value if true” Dimensions have an empty intersection.

Where Pigment addresses a Dimension difference, the hints:

- Explain which Dimensions were added for each argument.
- List all the Dimensions of the `IF` expression’s output as a whole.

## Dimension hints in arithmetic expressions

Pigment provides hints when a formula contains the arithmetic operators `+`, `-`, `*`, or `/`, and both of the below are true:

- the two sides of the operator reference Metrics (i.e. they have formulas of type `MetricA * MetricB`).
- the two Metrics have a different number of Dimensions.

Pigment resolves the formula and provides a hint explaining how Dimensions were aligned and how blank values were handled.