Before accepting an instruction, it is worth knowing whether the person in front of you already appears in one of the firm's matters, and in what role. JUDLEX checks this by itself when you add or edit a client, using their NIF.
When it appears
When you type the NIF / CIF in the client form and move to the next field, JUDLEX cross-checks it against two things:
The parties in all of the firm's case files. If that NIF appears as a party in another proceeding, for example as the opposing party, the warning appears with the role they have, the case file they appear in and the client that case file belongs to.
Your other clients. If a client with that NIF already exists, it tells you, because it may be the same client added twice.

It does not matter how the NIF is written, with dots, hyphens or spaces: it is the number that is compared.
What does not count as a conflict
It only warns you about someone who is a party to a proceeding. If a company appears in a paper for some other reason, because it issued an invoice, is the bank for a transfer or is an expert in another matter, that is a mention and does not trigger a warning. Warning you about every name that appears in a paper would fill the screen with false alarms.
It is a warning, not a block
The box tells you what it has found and nothing more. You can save the client anyway: the decision on whether there is a conflict, and what to do about it, is yours.