Clarification about AdParamService Documentation

I am a bit confused by the documentation here https://developers.google.com/adwords/api/docs/reference/v201609/AdParamService

It says:

"""

 default-value specifies the string to display if one of the following conditions is true:

• The parameter has not been set.

• The parameter's insertion text is too long for the display line.

• The ad is being shown on the Google Display Network.

"""

The confusing part is about the 3rd point: how come it's allowed to update the parameter that is then ignored if the ad is displayed on the Display Network?

Related to this question: what are the entities that can use the ad param?

Cheers,

    S-

--
--
=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
Also find us on our blog and Google+:
https://googleadsdeveloper.blogspot.com/
https://plus.google.com/+GoogleAdsDevelopers/posts
=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
 
You received this message because you are subscribed to the Google
Groups "AdWords API Forum" group.
To post to this group, send email to adwords-api@googlegroups.com
To unsubscribe from this group, send email to
adwords-api+unsubscribe@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/adwords-api?hl=en
---
You received this message because you are subscribed to the Google Groups "AdWords API Forum" group.
To unsubscribe from this group and stop receiving emails from it, send an email to adwords-api+unsubscribe@googlegroups.com.
Visit this group at https://groups.google.com/group/adwords-api.
To view this discussion on the web visit https://groups.google.com/d/msgid/adwords-api/b7f2f633-7034-4404-9d31-ab204052f8f4%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.