# A Deep Dive into Cursor Rules (\> 0.45)

**URL:** <https://forum.cursor.com/t/a-deep-dive-into-cursor-rules-0-45/60721>\
**Category:** Guides\
**Created:** [March 7, 2025, 9:13am UTC](https://forum.cursor.com/t/a-deep-dive-into-cursor-rules-0-45/60721 "2025-03-07T09:13:42Z")\
**Posts on this page:** 1\
**Showing post:** 9

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**Author:** ![raysefo](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/raysefo/32/39169_2.png) [@raysefo](https://forum.cursor.com/u/raysefo)\
**Post date:** [March 28, 2025, 12:39pm UTC](https://forum.cursor.com/t/a-deep-dive-into-cursor-rules-0-45/60721/9 "2025-03-28T12:39:36Z")

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I am new to Cursor, I wonder how can I apply rules to an existing application (developed without Cursor) so that I can add new features with Cursor?

Here is my post:

> [@Most efficient way to use rules](https://forum.cursor.com/t/most-efficient-way-to-use-rules/70545):
>
> Hi there, I am new to Cursor. I built an e-commerce Blazor web application without using Cursor. Now I want to add some new functionality to this application. I wonder what is the most efficient way to add rules? One big rule or separate rules would be more suitable? Here are some sample rules for different purposes: [cursor Blazor rules.txt](https://forum.cursor.com/uploads/short-url/bAOOr8HVpkuZ3wqltyTrhQwpgQM.txt) (4.9 KB) [cursor Bootstrap rules.txt](https://forum.cursor.com/uploads/short-url/xx8wwdI8sYk595hN1JqqiIS1E3Q.txt) (2.6 KB) Thank you in advance.

Thanks in advance.

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