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Kelly_Gault1
Kelly_Gault1
Level 2
May 5, 2025
Solved

Referrer Constraint vs _mktoReferrer field

  • May 5, 2025
  • 1 reply
  • 619 views

Looking for some help understanding something that I can't figure out from available docs and past discussions on the topic. Can someone please clarify the following?

 

1) When you use the referrer constraint with a Fills Out Form trigger, is the "Referrer" the page the form is embedded on? 

 

2) What part of the Fill Out Form activity in a person's activity log is equivalent to the Referrer constraint from the trigger? Is the "Referrer URL" (listed between "Query Parameters" and "Client IP Address")?

 

3) What is the "_mktoReferrer" field listed under Form Fields on the Fill Out Form activity in a person's activity log? Sometimes, this value is different from the Referrer URL. This_mktoReferrer URL plays no part in the Referrer constraint, correct? 

 

Just trying to figure out what is the best constraint to leverage with our global forms used on multiple pages. Our Web Dev team is concerned that the Referrer constraint does not consistently reference the page the form was submitted from. For extra context: we use Contentful rather than Marketo LPs.

 

Thanks so much for your help with clarifying something I should have a better grasp on this far into my Marketo journey.

Best answer by SanfordWhiteman

1) When you use the referrer constraint with a Fills Out Form trigger, is the "Referrer" the page the form is embedded on? 

Yes.

 

2) What part of the Fill Out Form activity in a person's activity log is equivalent to the Referrer constraint from the trigger? Is the "Referrer URL" (listed between "Query Parameters" and "Client IP Address")?

Yes, and also —

 

3) What is the "_mktoReferrer" field listed under Form Fields on the Fill Out Form activity in a person's activity log? Sometimes, this value is different from the Referrer URL. This_mktoReferrer URL plays no part in the Referrer constraint, correct? 

— _mktoReferrer is a hidden field submitted on every form. This is the field used by Marketo to set the Referrer URL. As such it should have exactly the same value. When are you seeing a difference?

1 reply

SanfordWhiteman
SanfordWhitemanAccepted solution
Level 10
May 6, 2025

1) When you use the referrer constraint with a Fills Out Form trigger, is the "Referrer" the page the form is embedded on? 

Yes.

 

2) What part of the Fill Out Form activity in a person's activity log is equivalent to the Referrer constraint from the trigger? Is the "Referrer URL" (listed between "Query Parameters" and "Client IP Address")?

Yes, and also —

 

3) What is the "_mktoReferrer" field listed under Form Fields on the Fill Out Form activity in a person's activity log? Sometimes, this value is different from the Referrer URL. This_mktoReferrer URL plays no part in the Referrer constraint, correct? 

— _mktoReferrer is a hidden field submitted on every form. This is the field used by Marketo to set the Referrer URL. As such it should have exactly the same value. When are you seeing a difference?

Kelly_Gault1
Kelly_Gault1Author
Level 2
May 8, 2025

Thank you so much for your quickly reply! I manage a team that is investigating the issue and, it turns out, there was some confusion around the referrer constraint, the _mktoReferrer field, and some custom referrer fields in our instance. Thank you for confirming my understanding of the constraint and the _mktoReferrer field--it has helped me shut down the assertion that some form issues we're experiencing are a result of the referrer constraint not actually being the page the form is submitted from.

 

I didn't want to muddy this post, so I opened another thread on the form issues here:

https://nation.marketo.com/t5/product-discussions/webinar-registration-triggering-the-submission-of-incorrect-form/m-p/356735#M203156

 

I really appreciate your help. Thank you for clearing up this detail!

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