# ATTDEF Command [GstarCAD 2021](Help%20System/GSTARCAD/2021/Index.md) → [Commands](Help%20System/GSTARCAD/2021/Commands/(Commands).md) → [A](Help%20System/GSTARCAD/2021/Commands/A/(A).md) The ATTDEF command is used to save data attribute definition in block. **Command Access:** > **Ribbon:** Home \> Block  \> Define Attribute > **Ribbon:** Insert \> Block Definition \> Define Attribute > **Menu:** Draw \> Block \> Define Attributes... > **Command:** ATTDEF (display Attribute Definition dialog box), -ATTDEF (display command line prompts) **Function Description:** >  > > The attribute of block could be contained in block definition. Users could save data in attribute, such as number of parts, product name, etc. > Inputting “-attdef” under the command prompt, it will display options. ## Other versions with matching text [GstarCAD 2016](../../../2016/Commands/A/ATTDEF%20Command--9e20769695e1.md) · [GstarCAD 2017](../../../2017/Commands/A/ATTDEF%20Command--9e20769695e1.md) · [GstarCAD 2018](../../../2018/Commands/A/ATTDEF%20Command--9e20769695e1.md) · [GstarCAD 2019](Help%20System/GSTARCAD/2019/Commands/A/ATTDEF%20Command--9e20769695e1.md) · [GstarCAD 2020](../../../2020/Commands/A/ATTDEF%20Command--9e20769695e1.md)