Graph names are text and up to 20 characters. Only letters, numbers, @, -, and . are allowed. All other characters are removed. It is recommended that names complying with this are used. Any graph name that you try and use that is too long will be replaced with one that uses part of the name and a hash to try and ensure a consistent unique graph name is applied.
Graphs can be defined in some configuration settings such as interface names.
The number of graphs is limited depending on memory, but the design is to allow for 100,000 distinctly named graphs. Dynamic circuits simply do not have graphs on them if this number is exceeded. Graphs not used for more than the data retention time are discarded automatically.