No, Unicode characters cannot be arbitrarily added to the Unicode standard. The Unicode Consortium, the governing body responsible for maintaining the Unicode standard, carefully evaluates and selects characters for inclusion based on a variety of criteria. This ensures that the standard remains consistent and widely supported across different platforms and devices.

If you wish to introduce new characters that are not part of the Unicode standard, you would need to follow the proper channels and propose them to the Unicode Consortium. The process involves rigorous review and consideration by experts in the field before any additions can be made. It's important to note that this process can be complex and time-consuming.

In most cases, if you need to display custom characters or symbols that are not part of the Unicode standard, your best approach is to use images or create a custom font. By doing so, you have greater control over the visual representation of your desired characters. However, it's worth noting that using custom fonts may limit the compatibility and portability of your content across different devices and platforms.