# How to use literals starting with "$" in iRule

**URL:** <https://community.f5.com/t/how-to-use-literals-starting-with-in-irule/52154>\
**Category:** Technical Forums\
**Tags:** devops, irules, http-header\
**Created:** [June 1, 2021, 1:12am UTC](https://community.f5.com/t/how-to-use-literals-starting-with-in-irule/52154 "2021-06-01T01:12:06Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Genna\_Reingold](https://avatars.discourse-cdn.com/v4/letter/g/f6c823/32.png) [@Genna\_Reingold](https://community.f5.com/u/Genna_Reingold)\
**Post date:** [June 1, 2021, 1:12am UTC](https://community.f5.com/t/how-to-use-literals-starting-with-in-irule/52154/1 "2021-06-01T01:12:06Z")

</div>

Hi,

I need to pass client certificate to WebSphere so the application can perform SSL based authentication. I following this article [myF5](https://support.f5.com/csp/article/K95338243)

However in WebSphere App Server the headed for client certificate is $WSCC. But if I code iRule like this

when HTTP\_REQUEST {

HTTP::header insert $WSCC [b64encode [SSL::cert 0]]

}

$WSCC is treated as a variable WCSS and the rule is broken

How do I get around this issue?

Thanks

Genna

---

<div class="post-metadata">

**Author:** ![Daniel\_Wolf](https://d1p9zq3aats0t8.cloudfront.net/user_avatar/community.f5.com/daniel_wolf/32/1119_2.png) [@Daniel\_Wolf](https://community.f5.com/u/Daniel_Wolf)\
**Post date:** [June 1, 2021, 4:58am UTC](https://community.f5.com/t/how-to-use-literals-starting-with-in-irule/52154/2 "2021-06-01T04:58:21Z")

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Hi Genna,

you can escape the ‘$’ character with a ‘\’. This should work:

```tcl
when HTTP_REQUEST {
    HTTP::header insert "\$WSSC" [b64encode [SSL::cert 0]]
}

```

KR

Daniel

---

<div class="post-metadata">

**Author:** ![Stan\_PIRON\_F5](https://avatars.discourse-cdn.com/v4/letter/s/e79b87/32.png) [@Stan\_PIRON\_F5](https://community.f5.com/u/Stan_PIRON_F5)\
**Post date:** [June 1, 2021, 11:53am UTC](https://community.f5.com/t/how-to-use-literals-starting-with-in-irule/52154/3 "2021-06-01T11:53:21Z")

</div>

to prevent variable substitution, you can replace double quotes by curly braces.

```tcl
when HTTP_REQUEST {
    HTTP::header insert {$WSSC} [b64encode [SSL::cert 0]]
}

```

Stan