sentences:  Unlike the documents and reports that are compiled in the Serial Set "hearings do not constitute a real series" although in the modern era a trend toward uniformity of numbering has resulted in all Senate hearings and prints for each Congressional Session (commencing with the 98th Congress in 1983) being assigned a unique numerical designation (in the style of what one scholar dubbed a "combination code") published on the cover and title page (e.g.S.