Why can column names not begin with an underscore? about nano-sql HOT 1 OPEN

if (!table._internal && (l.indexOf("_") === 0 || l.match(/\s/g) !== null || l.match(/[\(\)\]\[\.]/g) !== null)) {
                rej({ error: "Invalid Table Name " + table.name + "! https://docs.nanosql.io/setup/data-models", query: _this.query });
                return;
            }

if (!modelData[0] || modelData[0].match(/[\(\)\]\[\.]/g) !== null || modelData[0].indexOf("_") === 0) {
                    hasError = true;
                    rej({ error: "Invalid Data Model at " + (table.name + "." + col) + "! https://docs.nanosql.io/setup/data-models", query: _this.query });
                }