---
title: February 2021 VCL release ("Pakora")
summary: null
url: https://www.fastly.com/documentation/reference/changes/2021/02/vcl-changes
---

Today the minimum version of VCL available across our network increased, unlocking the following changes:

## Improved content

- We've renamed a bunch of function arguments in places where names were previously misleading; for example, arguments referred to as `pattern` despite not being regular expressions. These are now more correctly referred to as `subject` or `target`.
- Historically, we have used the word 'datacenter' to refer interchangeably to either a physical location at which Fastly has a presence, or to a set of Fastly servers acting together as a cache. These concepts are no longer always the same, and so references to 'data center' have been changed to reflect whether they, in each case, refer to a _site_ or to a _POP_.
- We better described the behavior of _not set_ values when assigned to `STRING` variables.
- The `client.sess_timeout` variable's default value was corrected: the reference incorrectly stated that this was 10 seconds when it is actually 10 minutes.

## Updated function and variable descriptions

We expanded the descriptions of a number of functions and variables, adding detail, code examples, and, in some cases, better explanations of error conditions or edge cases. There were updates to:

- `obj.ttl`
- `req.body`
- `client.geo.ip_override`
- `beresp.ttl`
- `xml_escape`
- `table.lookup`
- `subfield`
- `std.suffixof`
- `std.strlen`
- `std.replaceall`
- `std.replace`
- `std.replace_suffix`
- `std.replace_prefix`
- `geoip.city`