If we take MS Word as reference the context is explaining the "insert symbol" command. The numbers are merely codes "13579" for the characters. However Microsoft is not exactly a language authority so there could be other more technicaly suitable terms describing this term appropriately.
Depends on readership and the general context. Generally "symbol" should be safe and sound to use.

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Note added at 1 hr (2007-10-22 17:20:48 GMT) Post-grading
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Elaboration on K.Metzgers comment and generall contemplation:

I do not see why my explanation can be sincerely misleading. Those stuck with what is meant can very well follow what I meant! Afterall I also stated and emphasized that MS Word category and wording refers to it as symbols. On top of that
which translator would fish out my term and use it once another one has been chosen. In that event mine serves the purpose of providing explanation. Last but not least my wording can be appropriate under similar circumstances and can be cherished as such. No harm and IMO no need for a late disagree to discredit it for an unclear sake. It for sure does not display an act of saviourism or alike acts (like saving other translators from making a mistake because my answer is not necessarily fully an error).