| Call Number Ranges | Subjects | Level |
| BR | Christianity in Spain | 3b |
| BL/BP/BR | Islam in Spain & the Iberian Peninsula | 3b |
| BX | The Church in Spain | 3b |
| DP 1-402 | History of Spain | 3c |
| DP 505-(900.22) | History of Portugal | 3a |
| DS 133-151 | Jews & Marranos in Spain, Iberian Peninsula | 3c |
| HC | Economic History & Conditions in Spain, Portugal | 3a |
| HN/HQ | Social History, Family & Women in Spain | 3c |
| HN/HQ | Social History, Family & Women in Portugal | 3a |
| HT | Communities, Classes, and Race in Spain | 3c |
| HT | Communities, Classes and Race in Portugal | 3a |
| HX | Socialism in Spain | 3b |
| JN | Politics in Spain | 2b-3b |
| PC 4001-4977 | Spanish language (not limited to Spain) | 4 |
| PC 5001-5498 | Portuguese language (not limited to Portugal) | 3a |
| PN | Film & Performing arts, Spain | 3c |
| PN | Film & Performing arts, Portugal | 2b |
| PQ 6001-8929 | Spanish literature (just Spain) | 4 |
| PQ 9000-9326 | Portuguese literature (just Portugal) | 2b |
| Z | Bibliography of Spain (literature) | 4 |
| Z | Bibliography of Portugal | 3a |
Level 4 "Research Level" indicates a collection that contains the "major published source materials required for doctoral study and independent research."
Level 3 collections provide "Study or Instructional Support," from basic through advanced. Levels 3a, 3b, and 3c are subdivisions indicating increasing collection depth. Level 3 collections support study from the undergraduate to the Masters degree, "as well as other specialized inquiries," which may be interpreted to mean preliminary dissertation level research at level 3c.
Level 2 indicates a collection of "Basic Information" resources, 2a being introductory and 2b advanced.
*The primary collection level indicators (0-5) are those of the RLG Conspectus. The chart above utilizes the WLN Conspectus definitions which include subdivisions to provide a total of 10 collection depth indicators. See chart on Columbia University Libraries web page.