This web page does not contain any Priority 1 accessibility errors that Bobby can detect. However, certain items require human judgment; these are listed below. Please review these items; if none of these apply to your page, it qualifies for Bobby Approved status.

User Checks

User checks are triggered by something specific on the page; however, you need to determine whether they apply. Bobby Approval requires that none of them apply to your page. Please review these 2 item(s):

1. If a table has two or more rows or columns that serve as headers, use structural markup to identify their hierarchy and relationship. (2 instances)
   Line 579, Line 1322
   
2. For tables not used for layout (for example, a spreadsheet), identify headers for the table rows and columns. (2 instances)
   Line 579, Line 1322
   

The following 4 item(s) are not triggered by any specific feature on your page, but are still important for accessibility and are required for Bobby Approved status.

3. Ensure that descriptions of dynamic content are updated with changes in content.
   
   
4. Use the simplest and most straightforward language that is possible.
   
   
5. Avoid ASCII art.
   
   
6. If you can't make a page accessible, construct an alternate accessible version.
   
   

Bobby Approved status is assigned on the basis of Priority 1 items in the Web Content Guidelines. For a higher level of accessibility you may also want to examine Priority 2 and Priority 3 items. 2 Priority 2 issue(s) that Bobby has identified are presented below.

1. Use relative sizing and positioning (% values) rather than absolute (pixels). (671 instances)
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606, Line 609, Line 610, Line 613, Line 614, Line 617, Line 618, Line 621, Line 622, Line 625, Line 626, Line 630, Line 631, Line 634, Line 635, Line 638, Line 639, Line 642, Line 643, Line 646, Line 647, Line 650, Line 651, Line 655, Line 656, Line 659, Line 660, Line 663, Line 664, Line 667, Line 668, Line 671, Line 672, Line 675, Line 676, Line 679, Line 680, Line 683, Line 684, Line 687, Line 688, Line 692, Line 693, Line 696, Line 697, Line 700, Line 701, Line 704, Line 705, Line 708, Line 709, Line 712, Line 713, Line 716, Line 717, Line 720, Line 721, Line 724, Line 725, Line 729, Line 730, Line 733, Line 734, Line 737, Line 738, Line 741, Line 742, Line 745, Line 746, Line 749, Line 750, Line 753, Line 754, Line 757, Line 758, Line 761, Line 762, Line 766, Line 767, Line 770, Line 771, Line 774, Line 775, Line 778, Line 779, Line 782, Line 783, Line 786, Line 787, Line 790, Line 791, Line 794, Line 795, Line 798, Line 799, Line 803, Line 804, Line 807, Line 808, Line 811, Line 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1391, Line 1394, Line 1395, Line 1398, Line 1399, Line 1403, Line 1404, Line 1407, Line 1408, Line 1411, Line 1412, Line 1415, Line 1416, Line 1420, Line 1421, Line 1424, Line 1425, Line 1428, Line 1429, Line 1432, Line 1433, Line 1436, Line 1437, Line 1441, Line 1442, Line 1445, Line 1446, Line 1449, Line 1450, Line 1453, Line 1454, Line 1457, Line 1458, Line 1462, Line 1463, Line 1466, Line 1467, Line 1470, Line 1471, Line 1474, Line 1475, Line 1478, Line 1479, Line 1483, Line 1484, Line 1487, Line 1488, Line 1491, Line 1492, Line 1495, Line 1496, Line 1499, Line 1500, Line 1504, Line 1505, Line 1508, Line 1509, Line 1512, Line 1513, Line 1516, Line 1517, Line 1520, Line 1521, Line 1525, Line 1526, Line 1529, Line 1530, Line 1533, Line 1534, Line 1537, Line 1538, Line 1541, Line 1542, Line 1546, Line 1547, Line 1550, Line 1551, Line 1554, Line 1555, Line 1558, Line 1559, Line 1562, Line 1563, Line 1567, Line 1568, Line 1571, Line 1572, Line 1575, Line 1576, Line 1579, Line 1580, Line 1583, Line 1584, Line 1588, Line 1589, Line 1592, Line 1593, Line 1596, Line 1597, Line 1600, Line 1601, Line 1604, Line 1605, Line 1609, Line 1610, Line 1613, Line 1614, Line 1617, Line 1618, Line 1621, Line 1622, Line 1625, Line 1626, Line 1630, Line 1631, Line 1634, Line 1635, Line 1638, Line 1639, Line 1642, Line 1643, Line 1647, Line 1648, Line 1651, Line 1652, Line 1655, Line 1656, Line 1659, Line 1660, Line 1663, Line 1664, Line 1668, Line 1669, Line 1672, Line 1673, Line 1676, Line 1677, Line 1680, Line 1681, Line 1684, Line 1685, Line 1689, Line 1690, Line 1693, Line 1694, Line 1697, Line 1698, Line 1701, Line 1702, Line 1705, Line 1706
   
2. Avoid use of deprecated language features if possible. (536 instances)
   Line 9, Line 10, Line 13, Line 15, Line 17, Line 19, Line 21, Line 23, Line 26, Line 28, Line 31, Line 33, Line 36, Line 49, Line 51, Line 65, Line 84, Line 94, Line 96, Line 116, Line 137, Line 139, Line 156, Line 163, Line 176, Line 186, Line 188, Line 191, Line 204, Line 219, Line 222, Line 234, Line 245, Line 251, Line 254, Line 269, Line 272, Line 282, Line 291, Line 294, Line 306, Line 314, Line 324, Line 327, Line 334, Line 337, Line 348, Line 350, Line 352, Line 370, Line 372, Line 384, Line 394, Line 396, Line 409, Line 423, Line 433, Line 435, Line 447, Line 449, Line 464, Line 466, Line 477, Line 479, Line 488, Line 490, Line 503, Line 505, Line 512, Line 516, Line 519, Line 522, Line 526, Line 531, Line 536, Line 540, Line 542, Line 545, Line 549, Line 552, Line 555, Line 559, Line 563, Line 567, Line 569, Line 571, Line 573, Line 577, Line 581, Line 585, Line 589, Line 594, Line 598, Line 602, Line 606, Line 610, Line 614, Line 618, Line 622, Line 626, Line 631, Line 635, Line 639, Line 643, Line 647, Line 651, Line 656, Line 660, Line 664, Line 668, Line 672, Line 676, Line 680, Line 684, Line 688, Line 693, Line 697, Line 701, Line 705, Line 709, Line 713, Line 717, Line 721, Line 725, Line 730, Line 734, Line 738, Line 742, Line 746, Line 750, Line 754, Line 758, Line 762, Line 767, Line 771, Line 775, Line 779, Line 783, Line 787, Line 791, Line 795, Line 799, Line 804, Line 808, Line 812, Line 816, Line 820, Line 824, Line 828, Line 832, Line 836, Line 841, Line 845, Line 849, Line 853, Line 857, Line 861, Line 865, Line 869, Line 873, Line 878, Line 882, Line 886, Line 890, Line 894, Line 898, Line 902, Line 906, Line 910, Line 915, Line 919, Line 923, Line 927, Line 931, Line 935, Line 939, Line 943, Line 947, Line 952, Line 956, Line 960, Line 964, Line 968, Line 972, Line 976, Line 980, Line 984, Line 989, Line 993, Line 997, Line 1001, Line 1006, Line 1010, Line 1014, Line 1018, Line 1023, Line 1027, Line 1031, Line 1035, Line 1039, Line 1043, Line 1047, Line 1051, Line 1055, Line 1060, Line 1064, Line 1068, Line 1072, Line 1076, Line 1080, Line 1084, Line 1088, Line 1092, Line 1097, Line 1101, Line 1105, Line 1109, Line 1113, Line 1117, Line 1121, Line 1125, Line 1129, Line 1134, Line 1138, Line 1142, Line 1146, Line 1150, Line 1154, Line 1158, Line 1162, Line 1166, Line 1171, Line 1175, Line 1179, Line 1183, Line 1187, Line 1191, Line 1195, Line 1199, Line 1203, Line 1208, Line 1212, Line 1216, Line 1220, Line 1224, Line 1228, Line 1232, Line 1236, Line 1240, Line 1245, Line 1249, Line 1253, Line 1257, Line 1261, Line 1265, Line 1269, Line 1273, Line 1277, Line 1282, Line 1286, Line 1290, Line 1294, Line 1298, Line 1302, Line 1306, Line 1310, Line 1314, Line 1320, Line 1324, Line 1328, Line 1332, Line 1336, Line 1341, Line 1345, Line 1349, Line 1353, Line 1357, Line 1362, Line 1366, Line 1370, Line 1374, Line 1378, Line 1383, Line 1387, Line 1391, Line 1395, Line 1399, Line 1404, Line 1408, Line 1412, Line 1416, Line 1421, Line 1425, Line 1429, Line 1433, Line 1437, Line 1442, Line 1446, Line 1450, Line 1454, Line 1458, Line 1463, Line 1467, Line 1471, Line 1475, Line 1479, Line 1484, Line 1488, Line 1492, Line 1496, Line 1500, Line 1505, Line 1509, Line 1513, Line 1517, Line 1521, Line 1526, Line 1530, Line 1534, Line 1538, Line 1542, Line 1547, Line 1551, Line 1555, Line 1559, Line 1563, Line 1568, Line 1572, Line 1576, Line 1580, Line 1584, Line 1589, Line 1593, Line 1597, Line 1601, Line 1605, Line 1610, Line 1614, Line 1618, Line 1622, Line 1626, Line 1631, Line 1635, Line 1639, Line 1643, Line 1648, Line 1652, Line 1656, Line 1660, Line 1664, Line 1669, Line 1673, Line 1677, Line 1681, Line 1685, Line 1690, Line 1694, Line 1698, Line 1702, Line 1706, Line 1712, Line 1717
   

User Checks

4 Priority 2 issue(s) that Bobby has identified are presented below:

1. Check that the foreground and background colors contrast sufficiently with each other.
   
   
2. Use header elements in the proper sequence and not for bold text.
   
   
3. Avoid using tables to format text documents in columns unless the table can be linearized. (2 instances)
   Line 579, Line 1322
   
4. Mark up quotations with the Q and BLOCKQUOTE elements.
   
   

The following 8 item(s) are not triggered by any specific feature on your page, but are still important for accessibility.

5. Use a clear, consistent navigation structure.
   
   
6. Make sure your document validates to formal published grammars.
   
   
7. Where it's possible to mark up content (for example mathematical equations) instead of using images, use a markup language (such as MathML).
   
   
8. Use metadata to add computer-understandable information about the page.
   
   
9. Group related elements when possible.
   
   
10. Ensure that dynamic content is accessible or provide an alternate presentation or page.
    
    
11. Offer a site map or table of contents, and provide a description of the general layout of the site, the access features used, and how to use them.
    
    
12. Use the latest technology specification available whenever possible.
    
    

Bobby Approved status is assigned on the basis of Priority 1 items in the Web Content Guidelines. For a higher level of accessibility you may also want to examine Priority 2 and Priority 3 items. 2 Priority 3 issue(s) that Bobby has identified are presented below.

1. Identify the language of the text. (1 instance)
   Line 1
   
2. Provide a summary and caption for tables. (2 instances)
   Line 579, Line 1322
   

User Checks

2 Priority 3 issue(s) that Bobby has identified are presented below:

1. Provide abbreviations for long row or column labels. (2 instances)
   Line 579, Line 1322
   
2. Provided a linear text alternative for tables that lay out content in parallel, word-wrapped columns. (2 instances)
   Line 579, Line 1322
   

The following 9 item(s) are not triggered by any specific feature on your page, but are still important for accessibility.

3. Create a consistent style of presentation between pages.
   
   
4. Provide a link at the beginning of a group of related links to bypass the group.
   
   
5. Use icons or graphics (with accessible alternatives) to facilitate comprehension of the page.
   
   
6. Allow users to customize their experience of the web page.
   
   
7. Use the ABBR and ACRONYM elements to denote and expand abbreviations and acronyms.
   
   
8. Offer navigation bars for easy access to the navigation structure.
   
   
9. Place distinguishing information at the beginning of headings, paragraphs, lists, etc.
   
   
10. If ASCII art is present, provide a means to skip over it.
    
    
11. Offer different types of searches for different skill levels and preferences.
    
    

The following section contains a list of 2 browser compatibility errors. Browser compatibility errors help to determine when HTML tags and their attributes are not compatible with certain web browsers or HTML specifications. Browser compatibility errors do not affect the accessibility rating of a page.

1. Unknown attribute HTTP-EQUIV in element META. for browser(s): Lynx2.7 (1 instance)
   Line 3
   
2. Unknown attribute WIDTH in element TD. for browser(s): Lynx2.7 (274 instances)
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The following three-column table gives download time statistics for the images, applets, and objects on this page. The first column contains the URL of each item, the second column the item size in kilobytes, and the third column the approximate download time for each item when using a 28,800 baud modem. At the end of the report, an arbitrary delay of 0.5 seconds is added for each file to account for slow-downs caused by HTTP connection times.

URL	Size	Time (secs)
http://thunder.nsstc.nasa.gov/bookshelf/pubs/Obs_ligh_space.html	53.66 K	14.91
Total	53.66 K	14.91
HTTP Request Delays	--	0.50
Total + Delays	--	15.41