Word for a message that most people find plain but a smaller group see as supportive

Question

I feel like there's an idiom for this, such as if someone makes a comment that might seem innocuous at face value so you dismiss it, but another group of people who are more extreme might see as a sign that the person is on their side.

Something like "Well, some people, criminals, who are coming into this country don't belong here." Where a racist or a white nationalist might think "He supports our vision of the pure race," but the rest of us would think "Yeah, I don't want criminals coming into our country".

I feel like it's similar to "false flag" or something, but I can't remember quite the right word.

An example sentence, in response to a statement by someone else to call them out on their ____-ing:

What you're doing here is saying "This is Mexico's fault" but that's a ____ for people who don't think Mexicans belong here.

Answer 1

I think you mean a dog whistle

dog whistle noun

(TO CALL DOG) a whistle used to train dogs, with a very high sound that humans cannot hear

(POLITICS) (disapproving): a remark, speech, advertisement, etc. by a politician that is intended to be understood by a particular group, especially one with feelings of racism or hatred, without actually expressing these feelings: "Attacks on "political correctness" can be a dog whistle to rally white voters."

Answer 2

A shibboleth is a word or term that is only used in a certain way by a certain group of people, and it enables these people to recognise a fellow member. Outsiders may not notice anything out of the ordinary, and/or they may be unable to properly use the term.

Some general, tangentially related terms are sign, tell-tale, pejorative, dysphemism, discours.

Answer 3

This is sometimes referred to as coded [X] (where X is usually racism).

It's usually used by opponents of the speaker to imply the presence of the “dog whistle” ...

Answer 4

It's a logical fallacy known as conflation.

Conflation happens when the identities of two or more individuals, concepts, or places, sharing some characteristics of one another, seem to be a single identity, and the differences appear to become lost.1 In logic, it is the practice of treating two distinct concepts as if they were one, which produces errors or misunderstandings as a fusion of distinct subjects tends to obscure analysis of relationships which are emphasized by contrasts.

Conflation in logical terms is very similar to, if not identical to, equivocation.

(Source: Wikipedia.) You said:

Something like "Well, some people, criminals, who are coming into this country don't belong here.". Where a racist or a white nationalist might think "He supports our vision of the pure race" but the rest of us would think "Yeah I don't want criminals coming into our country".

In your example, the racist conflates the simple statement Well, some people, criminals, who are coming into this country don't belong here." with their own extreme beliefs; hence they incorrectly assume that the speaker is in agreement with them.

Whereas the more level-headed listener takes the statement at face value, without combining it with any extraneous, irrelevant meanings.