In Marketo String/Text fields, surrogate pairs must be URL-encoded, and you should encode line breaks
We like to think these are synonyms:
the value you tell Marketo to save
the value Marketo saves to the database
the output of a {{lead.token}}
But in fact, they can differ in interesting and largely undocumented ways.
Sometimes the saved value is truncated when the platform encounters a character it doesn’t like. Sometimes the saved value is what you expect, but the corresponding {{lead.token}} replaces original characters with new ones on the fly. And the behavior varies based on whether the update was sourced from a form, the API, or the Marketo UI.
The known offenders are:
line breaks: that is, real U+000A, not HTML <br> tags
surrogate pairs: any Unicode character requiring 2 paired bytes, such as common emojis like 👍 and 😛 and fancy arrows like 🡲 and 🡘 (plus hundreds of thousands of others, though most are archaic languages you’re unlikely to see in marketing data)
Line breaks are turned into space
