Difference between "Discriminant", "Discriminative" and "Discriminating"

Question

Let us assume I am writing some technical CS stuff, and I want to talk about "features" of something that discriminate something else.

Translating from my native language (French), I would use the word + adjective:

Discriminant features

However, I have stumbled in reads upon the word "Discriminative" and "Discriminating".

According to Wiktionary, we have:

Discriminant (Adj.): Serving to discriminate.

Discriminative (Adj.): Which has the ability to discriminate between things; or which imparts such ability

Discriminating (Adj.): Able to perceive fine distinctions between similar things; perceptive

So if I understand this correctly, Discriminating does not have the same meaning as the other two, i.e. discriminating is an adjective for someone/something that perceives the differences, instead of caracterizing them.

However it is not clear, with regards to the definition of Wiktionary, whether Discriminative and Discriminant are perfect synonyms, or if one is more used in some context than an other, or if they don't exactly mean the same thing, etc.

Answer 1

Almost right;

His comments about the attack discriminated against those people

or possibly

His comments about the attack were discriminating against those people who weren't involved. 

Back to the question; discriminant and discriminative are pretty much obscure and obsolete. Discriminate is almost exclusively used in its verbal form.

Discriminant is a noun describing a property that discriminates.

The discriminant between red squirrels and grey is their colour

Discriminative is an adjective and applies to the object but is not the same as discriminating = prejudice.

He was discriminative, disliking red sweets and liking green ones

Answer 2

Discriminating is used to describe something that a subject is doing. It is not an adverb because it does not describe a verb directly.

His comments about the attack was discriminating to those people who aren't involved.

As you can see in the example sentence. Discriminating was used to describe an action or something that he did. It was discriminating.

He is Discriminative when it comes to attacks. He always thinks it was everyone else's fault.

As you can see Discriminative is used to describe somone. He is Discriminative when it comes to attacks.