list of acceptable Unicode characters published for pdf name?

[inhk_2677]

Unicode characters used to be allowed as pdf names which allows view more characters in small smartphone display but I am finding previous characters no longer allowed 

Example where some of following are Unicode characters previously acceptable but no longer. 
would there be a list of acceptable Unicode characters published for pdf name?

乙巳㋉㏨㍨¼ :e_mail:Subject: 乙巳㋉㏨（）、？、！ 

[Amal.]

Hi there

Hope you're doing well and thanks for reaching out.

We understand your concern. The ability to use certain Unicode characters in PDF file names may vary depending on the device’s operating system, app version, or file system restrictions. In some recent updates, support for specific Unicode or special characters may have been limited to ensure better compatibility across platforms and cloud syncing services.

Currently, Adobe does not publish an official list of all supported or restricted Unicode characters for PDF file names. However, to avoid naming issues, we recommend:

Using standard alphanumeric characters (A–Z, 0–9) and basic symbols like underscores (_) or hyphens (-).

Avoid using emojis or special characters outside the basic Unicode range.

If you’ve noticed this change after a specific app update, please share the app version and device details so we can look into it further.

~Amal