" What does it actually produce?\n",
"\n",
"1. Some database designers prefer to use\n",
- " a [sentinel value](../../gloss.html#sentinel-value)\n",
+ " a [sentinel value](https://github.com/swcarpentry/bc/blob/master/gloss.md#sentinel-value)\n",
" to mark missing data rather than `null`.\n",
" For example,\n",
" they will use the date \"0000-00-00\" to mark a missing date,\n",