Yes
The adjective for "sign" is "symbolic" or "indicative."
True
For the most part, the shape of the sign is for only one thing. And that one thing is so you can recognize what type of sign it is at a further distance away (a diamond warning sign, you will know to slow down before you read what the warning is.)
that one sign, with that one shape to it... you know that tells you to do those one things
WHAT icons? If you are referring to the SHAPE of the signs themselves, the shape of the sign itself signifies the type of information the sign conveys. (e.g.: Octagaonal signs are ALWAYS stop signs - Diamond-shape signs ALWAYS convey some type of warning message - etc).
A stop sign is in the shape of an octagon.
A stop sign is octagonal in shape.
demonstrative pronouns
It is in the shape of a shield.
Changes in stool caliber can be indicative of underlying health issues because variations in the size, shape, and consistency of stool can be a sign of digestive problems, such as inflammation, infection, or obstruction in the gastrointestinal tract. Monitoring changes in stool caliber can help identify potential health issues early on and prompt further evaluation by a healthcare provider.
The pronouns that can show indicative type are "this," "that," "these," and "those." These pronouns indicate specific nouns by pointing to them in different ways (near or far, singular or plural).
A regulation sign is a sign that gives you the regulation for something. These signs are always in white and black and rectangle in shape. An example is a speed limit sign.