anchor.diff:  
   On the left side of the page you will see the available metadata attributes as facets that you can further use to refine your query. Picking one or more of these facets will limit the results displayed to those that match the newly specific criteria after you click on the button to apply the filters. Selecting the facet title will filter samples that contain the attribute, whilst selecting a facet value will more precisely filter samples that contain the attribute type/value pair. You can select combinations of both the facet title and one or more of the facet values. You can read more about this in the dedicated <<filters,filters section>>
   
  -If there are more than 10 results for a query then they will be split over multiple pages; to change page, use the controls underneath the facets on the left.
  +If there are more than 10 results for a query, your results will be split over multiple pages. You can jump through the pages using the controls underneath the facets on the left hand side of the page.
   
   == Advanced search
  -As simply entering the terms you wish to search for, there are some additional features of the search that might be useful to find samples of interest.
  +In addition to standard search, there are some additional features of BioSamples search that may be useful.
   
   === Double quotes
  -Sometimes you will want to search for a specific phrase and this can be controlled by surrounding the phrase within double quotes e.g. to search for breast cancer you can use: `"breast cancer"` . This will make sure that your results match your query entirely as adjacent words in the result, rather than matching just part of it or matching it at different parts of the result.
  +Surrounding a phrase within double quotes you can search for a specific phrase that spans multiple words.  e.g. to search for breast cancer you can use: `"breast cancer"` . This will ensure that your results match your query as intended as adjacent words, rather than matching part of the phrase or or matching words separately.
   
   === Boolean queries
   
  
positive.code: This behaviour can be modified by using boolean operators (`AND` `OR` `NOT`) and round brackets e.g. to find mouse or human samples that do not have leukmemia you can use: `NOT Leukemia AND ( mouse OR human )` .
  
  === Wildcards
  Queries containing star or question mark characters are treated separately. A star character will match any combination of zero or more characters e.g. `leuk*mia` will match to 'leukemia' and 'leukaemia' as well as 'leukqwertymia'. A question mark character will match any single characters e.g. `m?n` will match both man and men.
  
  NOTE: for technical reasons, wildcards cannot be at the beginning of words e.g. `?ouse` .
  
  === Range queries
  Certain attributes can be queried for ranges of matching values. For example for things that were last updated between the 1st and 4th of April 2014.
  
  Attributes that can be searched using ranges are:
  
  * Last update date e.g. `updatedate:[2014-04-01 TO 2014-04-04]`
  * Release date e.g. `releasedate:[2014-04-01 TO 2014-04-04]`
  
  NOTE: the date syntax is `yyyy-MM-dd` with a double digit month and day required.
  
  [#primitives-nulls]
  
  [#filters]
  === Filters
  
  The search interface provide a quick and easy way to filter the results based on attributes type and value. This is done
  using the facets available on the left side of the screen.
  
  Each facet represents an attribute with 10 of the most common values for that attributes. Clicking on the facet title
  will filter the results of your query to samples having the attribute with any value, while clicking on one of the facet sublist will filter the results to only show samples having that specific attribute type-value pair.
  
  You can compose filter using different attributes or even different values from the same attribute.
  Selecting different facets will produce an intersection of the results, like an AND operator between the filters, while selecting different values within the same facet will generate an union of the results, like an OR operation between the two filters.
  
  *NOTE*: To apply the filters you need to click the *Apply filters* button at the top of the facet list
  
  You can also try to create manual filter following the link:../references/filters[reference guide on filters, window='_blank']
  
  == Some search use cases
  In this section we will show some example of queries which could be of potential interest for the user
  
  === Filter samples by project
  Many samples uses the `project` attribute do describe which project they are part of. Some examples are the FAANG project, as well as HipSci or EBiSC.
  You can get a feeling of the projects using a filter on the project attribute. Note that if the facet for the project attribute is not available in the facet list, you can still hardcode th
  e filter in the URL as explained in the link:../references/filters[reference guide on filters, window='_blank']
  
  To show only the samples with a project attribute select the project facet from the facet list (if available), or add `filter=attr:project` to the url after the `search?`.
  You can see the result of such filter using link:/biosamples/samples?filter=attr:project[this link, window='_blank'].
  
  You should be able to see now the project facet on the left side of the page. You can select one or more values from it to further filter the results based on specific project[s]. Check out link:/biosamples/samples?filter=attr:project:FAANG&filter=attr:project:HipSci[this link, window='_blank'] to see a search for FAANG and HipSci samples.
  
  [#filter_by_external_archive]
  === Filter samples with data in an external archive
  Many samples in BioSamples have external data associated to them and stored in other archives, like ENA or ArrayExpress.
  If you want to filter your query to samples with data in a specific archive, you can do that using an link:../references/filters#_external_reference_data[External Reference Data filter, window='_blank'].
  
  To see what are the most used external archives with data associated to sample, select the `external reference` facet from the list of facets available on the left side of the screen, or add `filter=attr:external+reference` to the url after the `search?` bit.
  
  Check out the result page for this query link:/biosamples/samples?filter=attr:external+reference[here, window='_blank']
  
  
negative.code: Check out the result page for this query link:/biosamples/samples?filter=attr:external+reference:ArrayExpress[here, window='_blank']
  
  === Get sample metadata associated to an ENA accession
  You may have an ENA accession ID available but you need to retrieve the sample metadata associated to such accession from BioSamples.
  
  The best way to do this is to use an external reference data filter. You can read the details about this in the link:../references/filters#_external_reference_data[filters reference page, window='_blank']
  
  Using facets is the easiest way of creating filters in the UI, but for more complicated searches it is usually easiest to manually add the filter to the url.
  
  If for example you want to get all the samples associated to the ENA accession SRS359918, then just add  `filter=extd:ENA:SRS359918` after the `search?` part of the url.
  
  Check out the result of this filter at link:/biosamples/samples?filter=extd:ENA:SRS359918[this page, window='_blank']
  
  To check which are the most used archives in BioSamples, you can follow the procedure explained in the "<<filter_by_external_archive>>" section.
  
  
  
  