For example, if we use a Rest API to send an ID (19 digits for example) into one of our pages, this ID will be parsed and therefore unusable.
Java/Groovy : "7300304369714702521"
Here are some articles that explain this subject more in detail:
For this reason, it's recommended to return IDs in their String format in order to be sure that the content will be preserved.
Twitter's API's for example provide IDs in both number and string format (id and id_str) to avoid this known behavior.
I hope this article helps.