ATTRIBUTE (ATTDEF) — Define Text Attributes in AutoCAD

AutoCAD ATTRIBUTE (ATTDEF) Command Access

Introduction

Attributes are one of the most powerful tools available in AutoCAD for creating intelligent drawings. An attribute is a text-based data field stored inside a block. When someone inserts the block, AutoCAD prompts them to enter values—such as sheet numbers, project names, dates, initials, and other information that varies from instance to instance.

The ATTDEF command (Attribute Definition) is how you create these attributes. It opens a dialog box where you set the tag, prompt, default value, formatting, and attribute behavior. After defining one or more attributes, you place them in your drawing and then include them in a block.

This article explains every option in the Attribute Definition dialog box, how attribute order affects user prompts, and how to use attributes effectively in title blocks, symbols, and other repeatable content.

What Are Attributes in AutoCAD?

Attributes are editable text fields embedded inside blocks. They allow each inserted block instance to store different information—something normal text cannot do.

Common uses include:

• Sheet titles and sheet numbers
• Project name and project number
• Drawn by / Checked by fields
• Revision information
• Symbol labels
• Annotation markers (section cuts, elevations, etc.)
• Equipment tags
• Data extraction for schedules and tables

Every attribute includes three essential components:

1. Tag — the internal name AutoCAD uses
2. Prompt — the message shown to the user
3. Default value — the starting text

Once attributes are part of a block, inserting that block displays a pop-up window showing each attribute in the order you originally selected them. This detail is extremely important for usability and consistency.

The Attribute Definition (ATTDEF) Dialog Box

Running the ATTRIBUTE or ATTDEF command opens a comprehensive dialog with all the options needed to define an attribute. Below is a detailed breakdown of each component and how it affects behavior.

The Attribute Definition dialog box includes the tag name, prompt, default value, text style settings, and attribute modes.

1. Attribute Category Options

Tag

The Tag is the internal name for the attribute.

• Must be unique within a block
• Should be in ALL CAPS
• No spaces; use underscores if needed
• Avoid renaming Tags later because it can break data extraction and standards

Examples:

• SHEET_NUMBER
• DRAWN_BY
• PROJECT_NAME

Prompt

This is the text AutoCAD displays to the user during block insertion.
Examples:

• “Enter sheet number:”
• “Drawn by:”
• “Project name:”

Make prompts clear and human-friendly.

Default Value

This is what appears automatically in the attribute unless the user types something else. You can leave this blank if you want the user to always enter a value.

If the attribute is Constant, the default becomes the permanent text displayed.

2. Text Settings

Text Style

Choose a text style from your drawing.

Common choices:

• ROMANS
• Annotative text styles
• Office standard styles

Justification

Determines how text aligns relative to the insertion point:

• Left
• Right
• Center
• Middle Center
• Fit

This is essential for precision placement.

Text Height

Determines the size of the attribute text:

• Title block attributes often use 0.125” or 3.5 mm
• Annotation-based attributes may vary depending on scale

Rotation

Sets the text angle.

• 0° is horizontal
• 90° is vertical
• Other angles are used for symbols or architectural conventions

Annotative

When checked, the attribute scales with different annotative scales.

Use only when the block needs to appear at multiple scales automatically.

3. Attribute Modes

These options change how AutoCAD treats the attribute.

Attribute Modes Explained

Mode	Behavior
Invisible	Attribute is hidden in the drawing but still stored.
Constant	Attribute cannot be edited during block insertion.
Verify	AutoCAD asks the user to confirm their entry.
Preset	AutoCAD skips prompting if a default value exists.
Lock Position	Prevents the attribute from being moved.

Notes:

• Constant attributes are perfect for fixed text like company names.
• Invisible attributes are ideal for metadata.
• Lock Position is strongly recommended for title block attributes.

Inserting the Attribute into the Drawing

After clicking OK in the dialog box, AutoCAD prompts you to pick an insertion point.

Placement matters:

• Insertion point determines alignment
• Justification affects layout
• Title block attributes should be placed very precisely

After defining the attribute, click to place it at the correct location in your title block or symbol.

Adding Attributes to a Block

Attributes only work when they are part of a block definition.

To include them:

1. Draw your geometry
2. Create each attribute with ATTDEF
3. Run the BLOCK command
4. Select the geometry and the attributes
5. Choose a base point
6. Give the block a name
7. Save it

The attribute selection order matters

During block creation, select attributes in the order you want them to appear in the pop-up window.

This small detail greatly improves usability—especially in title blocks.

Select both the attribute and the drawing geometry when defining your block.

Editing Attribute Values After Block Insertion

Once a block containing attributes is inserted, values can be edited using:

• EATTEDIT (Enhanced Attribute Editor)
• ATTEDIT (Legacy editor)
• Double-clicking the block

The Enhanced Attribute Editor allows users to:

• Change values
• Modify text height
• Adjust justification
• Change layer
• Toggle visibility

However, Tags cannot be changed this way. Changing a Tag requires redefining the attribute and then redefining the block.

The Enhanced Attribute Editor allows you to edit attribute values after inserting the block.

Tips for Using Attributes in Title Blocks

Attributes are essential for modern title blocks. Here are best practices:

• Use ALL CAPS for Tags
• Group related fields together (project info, sheet info, revision info)
• Make prompts clear and short
• Use Constant attributes for fixed fields
• Lock attribute positions after placement
• Avoid annotative attributes unless necessary
• Maintain consistent text styles

Title blocks typically include attributes such as sheet number, drawn-by information, and project details.

When to Use Constant Attributes

Constant attributes are excellent for:

• Company name
• Address
• Standard notes
• Revision block labels
• Symbols with fixed identifiers

Unlike normal attributes, Constant attributes never prompt the user—they simply display the default value every time.

Extracting Attribute Data

Attributes enable powerful automation tools such as:

• Schedules
• Material lists
• Parts lists
• Index sheets
• Excel exports

Use the DATAEXTRACTION command to collect attribute values and output them to tables or files.

To ensure reliable extraction:

• Use consistent Tag naming
• Maintain uppercase
• Avoid renaming Tags
• Use identical attribute definitions across related blocks

Common Attribute Mistakes

Avoid these frequent Attribute mistakes:

• Using inconsistent naming (e.g., SheetNum vs SHEET_NUMBER)
• Forgetting to lock attribute positions
• Changing Tag names after release
• Leaving attributes out of the block definition
• Selecting attributes in the wrong order
• Accidentally checking Invisible or Preset

Attribute Modes

Attribute Modes Explained

Mode	Description	Common Uses
Invisible	Hidden from view but still part of the block.	Metadata, automation fields, IDs.
Constant	Not editable during block insertion.	Company name, static labels, fixed notes.
Verify	Prompts twice to confirm entry.	Critical fields such as sheet number.
Preset	Auto-fills the default value without prompting.	Symbols with standard values.
Lock Position	Prevents attribute from being moved.	Title blocks and templates.

Related Commands and Tools

Related Commands and Tools

Command / Tool	Description
BLOCK	Creates block definitions that contain attributes.
EATTEDIT	Edits attribute values after block insertion.
ATTEDIT	Legacy attribute editor.
DATAEXTRACTION	Extracts attribute information for schedules and tables.
BATTMAN	Manages attribute order and settings inside a block.

FAQ — ATTRIBUTE (ATTDEF)

Summary

The ATTRIBUTE (ATTDEF) command is the foundation for building intelligent, editable, and data-rich blocks in AutoCAD. Understanding Tags, Prompts, Default values, Attribute Modes, and block selection order gives you full control over how information is entered and managed. Once set up correctly, attributes save massive amounts of time and ensure consistent, professional drawings across your entire project or office.