Title: Cache Personalization: Use substr over ltrim for stripping cookie value Author: WordPress VIP Documentation Published: October 12, 2021 Last modified: August 5, 2025 --- 1. [Changelog](https://docs.wpvip.com/changelog/) 2. [VIP MU plugins [Production]](https://docs.wpvip.com/changelog/vip-mu-plugins-production/) 3. Cache Personalization: Use substr over ltrim for stripping cookie value # Cache Personalization: Use substr over ltrim for stripping cookie value --- 12 October 2021 11:00:16 GMT+0000 [ VIP MU plugins [Production] ](https://docs.wpvip.com/changelog/vip-mu-plugins-production/) [ Permalink ](https://docs.wpvip.com/changelog/vip-mu-plugins-production/cache-personalization-use-substr-over-ltrim-for-stripping-cookie-value/) When encryption is enabled for cache grouping. [https://github.com/Automattic/vip-go-mu-plugins/pull/2485](https://github.com/Automattic/vip-go-mu-plugins/pull/2485)